There is a vast array of technology that would be "useful" but is simply far out of my price range, so I'll never use it. Like a personal jet, or a self-driving car.

I'll also never pay the increased price for similar performance of a laptop rather than a desktop PC. Yes, obviously mobility is useful in principle, but in practice I simply don't need it, and if I really needed to I could just use a tablet or very cheap notebook to remotely control my desktop.