TV scale large UI elements and tiny screen large UI elements are actually pretty similar. If your game supports being played on a tv at couch difference it probably will work on a small screen as well. Most games support TV scale UIs so it's not a problem.

99% of the time it's not a problem. When it is a problem you can bind a screen magnifier to a key. I still wouldn't want to play some games on it, games that require extensive typing (duskers is a game about piloting drones through a command line, wouldn't want to play that without a bluetooth keyboard), but for the most part it's fine. Most games, even text heavy ones, have big old fonts and large UI elements.