I think there is an automotive parallel here. Lets call a standard AR a Camaro. Slap a couple of high speed, useful accessories on it, and now you have a Corvette. Add a 10.5" Leitner-Weise gas piston upper with a freefloat rail, a Noveske brake and an Eotech 553, and now you have a NASCAR Monte Carlo.
Most people get buy with a car that will do 100. Some want at least 120. Or 150mph. There aren't a lot who need to do 200. Since I don't drive anywhere I could go 200mph, I don't need to spend the money on something that will do it. My AR is kind of the same way. I don't know if I've got one at Corvette level, but I'm happy with mine. They will do everything I can conceive of needing to get done. If I'm ever in an occupation where I need 200mph, then I'll prioritize getting that piston upper.