But a move like in TFA wouldn't be just old games. It would be literally every game I own except Forza Horizon 3 and Gears of War 4 (the only UWP games I own).

But a move like in TFA wouldn't be just old games. It would be literally every game I own except Forza Horizon 3 and Gears of War 4 (the only UWP games I own). New games still max out hardware - that's what I buy the hardware for. I own over 600 games on Steam and many others on Origin/UPlay/GOG. I would rather use an unsupported, unpatched OS to access those games than simply lose access to them because MS wants to "modernize" something that doesn't need changing.