Structural rigidity. Makes sense. I’ve had my Jeep on 3 wheels a few times. I took this one of my brother doing it. I’ll do it with my Outback but I haven’t yet.
This is the reason that I’m working on my third Honda Odyssey minivan. I did not set out to own a minivan. When the transmission was beginning to act up on the station wagon, I went looking for the smallest 3-year-old used car I could find that would hold my dog crate. Sigh. It turned out to be a van.
About the third day I was driving the van, I noticed that my knees were feeling better. I figured out that it was because I could just open the door and sit. No up, no down. I have never looked back. Sadly, I had been looking for a smaller car to keep relatives from borrowing my car to haul things. Going from a station wagon to a van did not reduce that at all. I make them take out the back seats, if that’s needed. I’m old enough that doing that is ungainly.
While I have always driven sedans, I have already decided that my next car is going to be a crossover or possibly a minivan. I am ready for a vehicle that does not require bending to get in and out of.
At the age of 70, butt-height is indeed a major consideration for me. My own car is a 2007 RAV4 and, once I put extender rails on the driver’s seat, I slip into it beautifully. It’s a pleasure to get in and out.
My wife’s car, which I drive pretty often and on long trips, is a 2016 CR-V. I have to lower the seat quite a bit in order to give my knees enough room and getting in and out is more of an effort. I was quite surprised that it would differ so much from the RAV4.
My 71 YO friend just bought an Accord hybrid. It is a big pain for me to get in and out of that. My friend has had knee surgery, as well as some pins put into his ankle after a slip and fall, and I asked him if he had considered the height of the seat when he made the purchase. He apparently did, but the whole “new hybrid car” fever had him in its grasp. The last couple times we’ve taken his car to lunch, I’ve noticed how gingerly he gets in and out. (We’re both over 6’ tall and 200+ pounds.)
When I was 45, I drove an Eclipse with zero complaints about the seat height.
I’m 5’6" tall and my Honda Fit is fairly short as well, I’ve driven crossover SUVs as rentals on business trips and would like to get one next time, just for the higher driving position.
I’m 65, fully spry, and drive a low sports car. I have many friends in their 70s who refuse to ride with me entirely because getting in and out of my car is too hard for them. They all drive slide-right-in crossovers.
In fact I was having exactly this conversation last night as I was riding in the Suburban piloted by my 70yo dinner companion who refused to ride in my car. He’s quite tall, and his 'burb isn’t raised, so for him the seating height is just a slight lift up and in. For smallish me it’s much more of a climb.
I was discussing that just looking at the calendar, I probably have a couple more years in this car, then one more sports car in me, then it’ll be my time for a slide-in too.
It’s a better design in a couple of ways. First of all, you are sitting higher. I had an Elantra before my H-RV, and it seemed like 90% of the vehicles around me rode higher, and the drivers could see more. More importantly, however is the fact that my H-RV is a little bigger than my Elantra, but it can hold much more and much bigger loads. I really like it and would never go back to the traditional automobile.
Which of course is a form of arms race.
Now that most people are driving SUV/crossovers, the only way to sit higher and see more than other drivers is to switch to a pickup truck. Then a lifted pickup truck. Then a Peterbilt. etc.
Of course there are practical limits, but the feedback loop when we as a collective of individuals try to out-anything everyone else always comes back to bite us at least partially.
There is an answer to that. Kind of unAmerican-ish, but it works for me: put everyone else farther away. It is kind of possible to acquire more visibility in a lower vehicle by adjusting your driving habits. Americans tend to pack up, but you are not absolutely required to do that. Expanding your space also makes driving a less stressful experience, most of the time (as long as you can ignore the bumper glue that tend to ride up on you when you are not packing up).
I have found that riding lower reduces my tendency to go faster. This is a good thing in terms of tickets and fuel consumption and things killed by me. Riding higher, I firmly believe, just reinforces the worst of our road behaviors.
Oddly, I have a pair of very comfortable shoes. I know they’ll only be available for a certain number of years before being discontinued. I’ve been wondering how many pair I’d need to buy to last until I no longer need shoes.
They are comfortable and easy to get on and off.
A car blog I read has argued that crossovers are nothing more than a return to the basic proportions all cars had prior to about the mid-1950s – the author points out that most modern midsized crossovers have roughly the same dimensions as a 1950 Plymouth station wagon. The long, low sedans and wagons we’ve become accustomed to since the late 1950s were designed with that shape for styling reasons, not practicality. He argues that the crossover actually represents a return to a more rational vehicle shape. A taller vehicle means passengers can sit more upright, which means you can fit more passengers in a smaller overall footprint since they don’t have to sit with their legs stretched out in front of them.
I bow to your superior Photoshop / AI / Google-fu. 
But you know somebody somewhere is building one of those for the Monster truck circuit.
Imagine how expensive something like that would be. Also, I have a feeling that auto parts for it would be very hard to come by. LOL
They buy a Caterpillar Mining Trucks chassis and put a fiberglass Hummer-like shell on it. Parts are readily available, if kinda pricy.
Yeah. It drives me nuts.
Really, all my driving is on twisty mountain roads. half the time they are snow covered. Even in that situation I get some idiot that tailgates. I drive an SUV, and these fools get right on my ass, not leaving any stopping distance and totally screw up there own ability to react to a hidden or surprise danger.
Nearly every time I go anywhere, I pull over and let these idjits go ahead of me.
Well, aerodynamics are a big factor too, and fuel efficiency does matter. Stability and handling are also improved in low vehicles.
Regarding slide-in slide-out and seating height, that’s not entirely a car vs non-car thing. I’m a big guy and I drive a Mazda 3. It’s no problem. A coworker drives a Tesla Model 3, and though they look to be basically the same size and shape, the Tesla is much MUCH harder to get into. I attribute that to a more steeply raked windshield cutting off headroom at the doors. As for sitting higher, it makes you feel like you’re going slower, and what fun is that? Also, what are you trying to see? Something in front of the vehicle in front of you is of little consequence since that vehicle is what you need to be paying attention to.
For a country that professes to love driving so much, it’s sad that most of the vehicles Americans drive are so bad at it.
This getting in and out of car business. I notice lots of people seem to have forgotten how to get into cars. How ableist am I being? I know that flexibility and balance issues can make things that seem easy be difficult for some people. The problem I see is that it seems to be an issue of technique as much as anything else.
I had to think about what I was doing to figure out how I get in a car. I stand next to the opening while facing forward. I put the car-side leg into the car, then I lower my butt into the seat, and then pull in my other leg in.
The people I see having trouble do things like go headfirst into the car. I’m not sure how that is supposed to work, but I’ve seen several different people try it.
The other option seems to be going butt first. I think that is the way people get into SUVs. Stand with your back to the car, sit on the seat, and then rotate to bring both legs in. Here the problem doesn’t seem to be the height of the seat, but more how low the roof line is. If the roof intersects the arc your head travels while moving, then this method is much more difficult to pull off.
Driving is not supposed to be fun IMHO. It’s a deadly serious task.
My 4Runner is a basic SUV. I, like others have said, find it easier to get in and out of. And, of course it’s snow/off road ability, and capacity. Brought home a 65" tv, sound bar and a 3’x2’ foot mirror two weeks ago.
As far as sight, you might see an animal in the road, or a disabled vehicle sooner. Regardless if someone is in front of you or not. I do not count on the person in front of me to be a good driver.
I had sporty cars when younger. I do remember literally dragging my Nissan 240SX the last few hundred yards home with my truck when it could not handle the snow. Put it in neutral, locked the steering wheel and hooked up a chain. The car had 4 studded snow tires, was 2 wheel drive and lacked any kind of ground clearance.
This maneuver is quite difficult for many people.