The issue of racecar drivers has been touched on, but I’d like to repost some comments I made in 2005 in response to similar claims about how “easy” it is to be a pro driver. (I have edited it slightly to update some factual and style issues.)
Driving a top level racing car (e.g. F1, IndyCar, NASCAR, and some sports car series) is arguably one of, if not the, most challenging forms of athletic competition in the world, taking into account not only the physical, but also the mental aspects.
The physical difficulty is far greater than is generally understood by people who’ve never driven or ridden in a racecar. There are the G forces and other strength requirements Fridgemagnet spoke of, and the fact that, unlike almost any other sport, except marathon running and long-distance bicycle racing, a racecar driver must keep that effort up for two hours or more with virtually no breaks. (BTW: pit stops are not relaxation breaks: most drivers’ heart rates are higher in pit stops than in any other part of the race except the start and the finish. Besides, they only last between 2 and 20 seconds.)
So from a physical standpoint, a driver needs greater endurance than a player of almost any ball sport, none of which (IIRC) requires more than 20 minutes of continuous play.
Furthermore, a car moving at 220+ MPH (350 KPH) is travelling a the length of a football field every second. To make a turn at precisely the right point requires faster reactions than are needed in any other sport.
Oh, and the cockpits of these cars can easily get to 130-140 degrees F. For two hours.
On the mental side, drivers need to be engineers, capable of determining from feelings, sounds, sights, even smells, what the car is doing, and which of the hundreds of possible engine, transmission, suspension, or tire adjustments might be needed to make it perform even better. They need to communicate these to the team so they can be ready to execute them in the next pit stop.
They need to know strategy not just against one other team, as ball sport players do, but against a dozen or more teams, represented by 20 or 30 other drivers. They have to know the abilities of every other driver, who is safe to run side-by-side with, who is unpredictable, whose teams’ equipment may be more likely to break, etc., etc.
They need to maintain laser-sharp mental focus for the entire length of the race. A tiny slip of concentration can put them into a wall.
And here’s the bottom line: unlike virtually any other sport, if racecar drivers don’t do everything right, they could DIE. Fortunately, safety systems are constantly improving, and fatalities are now much rarer than in the bad old days, but they still happen.
So I think race drivers are certainly among the best athletes in the world, and pro level racing is among the most challenging athletic competitions going.
To the point of this OP, when it comes to determining the gap between talented amateurs and pros in motorsports, the problem is that no amateur can possibly afford the immense sums of money needed to get into pro level equipment. In many sports, talent can show through regardless of the equipment. Anyone reading this thread could almost certainly afford to buy the tennis rackets and shoes used by Serena Williams.
OTOH, the top F1 teams spend as much as $400 million a year to field two cars. IndyCar and NASCAR budgets are in the tens of millions. Elon Musk could afford to have a go at pro racing; the rest of us, not so much.
You don’t just go from racing your Miata on weekends or doing High Performance Drivers Ed in your Corvette to driving in F1. Getting to the top levels of motorsports requires not only talent, but generally starting out as a child no older than about 6, with parents with enough money and dedication to devote to taking the kid to dozens of kart and junior series races a year for many years, and then the luck of finding sponsors who will support them through the ladder series to the point where a top team will notice and give them a try.
There are undoubtedly hundreds or thousands of people who might have the raw talent to be a top F1 driver, but will never get the chance. It’s impossible to know.