Get the ps5 then. You can play every xbox game on your One S except Flight Simulator, Scorn and Gotham Knights. They won't look as good as they will on Series X but you have access to them. Anything else that is current gen only is on PS5.

PS5 starts you off with 19 classics + 3-5 games per month if you get the base $60 subscription. The $100 subscription will get you this plus another 400 games. Many if which will are the PS exclusives you've been missing.