The general gamer playing on a 32-50" TV isn't gonna notice but the smoother framerate possible with optimized graphics will be in plain sight. I got a 60" 4K I throw my rig on for guest sometimes. It's nice but requires too much power and sacrifice of more important things considering something like a console won't have the same capabilities as a gaming pc. We're about 2 gens away from 4K being the standard without compromise.
Well some games can run 4k 60fps with no problem such as NBA2k I know madden and sports games will. Titles such as Battlefield can do it if they sacrifice particles n shyt lol. It is doable but not for all titles