It works well. I have a throwaway pseudonym dedicated to my appleTV and we use the login so infrequently that we always have to look it up.

The only time we ever interface with apple is to install a new app on the AppleTV and that is very rare.

The appletv is not connected to any other apple products or services.

I'm not any more in the ecosystem than an Apple ID and airpods, and it is just fine. The directional spatial audio with the airpods is cool, but we also use other BT headphones with it. I use the ATV almost exclusively for Jellyfin/Infuse.