The funny thing is that we started buying MORE games after getting it and filtering steam for the ones that work best.
It completely replaced the Nintendo Switch as our party platform, we have been adding piles of local multi player games to it and using multiple Xbox controllers with it docked around the main TV most of the time.
I think when it comes to how many titles work it is going to depend on your gaming preferences. If you play a lot of EA games or Ubisoft games it is clunky to get their store loaders going sometimes or at a min you get prompted to sign in via onscreen keyboard which is a PITA sometimes and there is lower support.
Steam native games however are great.
The ones I need, otherwise I always prefer core HA elements if possible.
With recently UI improvements in HA I have actually removed several HACS