You don't need to be in the Apple ecosystem to buy an Apple TV and only use non-Apple services.
The only thing that will probably suck is the lack of things like MiraCast and Google's Casting stuff, but you could use third party AirPlay software (still free IIRC) to stream whatever you want if you want to use screen mirroring.
These days people tend to use their media boxes as App Launchers for other services anyway, so it doesn't really matter that much anymore.
Yeah, the Apple TV would be my suggestion as well even if it's your only Apple device. Other than streaming service apps (Netflix, Hulu, etc...) I think the only app I've installed is Tailscale. It's a great device that is slightly more privacy respecting than similar devices from Roku or Smart TV manufacturers.
I've never owned a Mac before but now I'm thinking about getting one just so I can write software to run on my Apple TV. It's a pretty powerful computer that's tiny, silent, always on, barely uses any power, and is connected to my TV.
I'm going to check out VLC though. Thanks for the tip.
One other app that I had and forgot about is some remote play client for Steam. I start Steam on my desktop PC then pair my PS5 remote to the Apple TV, start the Steam tvOS app, and I can play games from my PC on the Apple TV.
The only thing that will probably suck is the lack of things like MiraCast and Google's Casting stuff, but you could use third party AirPlay software (still free IIRC) to stream whatever you want if you want to use screen mirroring.
These days people tend to use their media boxes as App Launchers for other services anyway, so it doesn't really matter that much anymore.