Not sure why you’d think steak was no good on a gas grill. Unless you have one that doesn’t get hot enough. The whole point of a good steak is to sear quickly over very high heat, then (if it’s really thick) to set it aside on indirect heat to cook through. A 1 inch to 1.5 inch thick steak should do just fine on a typical gas grill, as long as it can reach 700F.
The main reason to get a NP gas grill is to avoid having to deal with the propane tank level, it’s just hooked up to the gas line of your house. If you don’t have a problem with gas grill vs. charcoal in the first place, you’ll be fine. I’ve used one for 20 years, all Weber models.
I enjoy it for the ease of getting it started for quick cooking, medium to high heat foods like steaks, burgers, and hot dogs. Plus the oven-like convenience of “set and forget” on longer cooking foods, like large roasts, multiple chickens or racks of ribs, etc., that would never fit in my oven. I’ve had no complaints about the taste of the food, either.
Yes, you don’t get the smoky taste of charcoal cooking, but that’s fine with me. The flavor in what I grill comes from the rubs and spices and sauces, and the quality of the meat itself. Not everything that is grilled needs to be smoky.
And even then, for quick or even medium length cooked stuff, like steak or chicken drums and thighs that grill for about 40 minutes, I find I can get a smoky flavor added if I want to just by using unsoaked wood chips in a metal wood chip box placed between the (gas) fire and the grate as the grill preheats. In theory I could throw a few chunks of charcoal into that box, too - I may try that next time!
That said, I have been contemplating getting a charcoal SMOKER for the stuff that I do want that smoky flavor in it, that my gas grill cannot do: low and slow cooked stuff. Pulled pork, certain styles of BBQ ribs, briskets, that kind of thing.
That’s the only scenario where I’ve concluded yes, the gas grill just isn’t up to the task. But that’s a minority of what I consider grilling. “Grilling” is NOT synonymous with “BBQ.”