You can just use any 30-50 €$£ Android stick and stuff it with Android apps. Keep the TV as a monitor.
Until a month ago I was using an old Android 5 TV. It can still do so many things.
I suggest using NewPipe (or NP x SponsorBlock) 0.24.1 as that had a better layout for large screen. Not sure if they fixed it in 0.25.x yet.
Some other YT apps are actually specialised for TV use so you may wanna try more of them too.