I'm new to sub and android Tv devices. Do android Tv devices have regular Google Play store and does it have all apps like Xbox game pass (for cloud streaming)? Or do manufacturers replace Google store with custom one with only approved apps? Especialy asking about new Google tv device. Also is Google tv best device to buy in its price range? Or would mi box s be better?
Android TV devices have the Android TV Play Store which has only Android TV optimized apps. You can install the apk of mobile apps (this is called sideload) and sometimes get good results.
Microsoft has the Game Pass app for Android phones and tablets but not for Android TV. Sideloading may or may not work (it works in Nvidia Shield for instance, we don't know about the new Chromecast)
https://9to5google.com/2020/09/16/android-tv-xbox-game-pass-ultimate/#more-378779