I set up a Linux pc to replace my smart TV and add some gaming capabilites. It took some time but I learned quite a lot (Thanks to Debian and Arch wikis). And I haven't missed any TV functionality.
The launcher is flex-launcher on a labwc environment/compositor on a Debian stable distro. (For testing and easy setup, I also did it on Ubuntu Gnome but I don't need a full DE in the background that I don't use. But it's adaptable to other distros and DEs.)
It's now fully usable with a gamepad including turning the TV on and off, so I have also fully replaced the TV remote.
I hope some people may find it interesting. It was also quite a lot of fun, actually.
Do you have to login all the time? I run mint on my TV on a mini pc and it's fine but having to login is a pita. I tried to make it login less but it didn't like it and I think it broke some things.
I'm using autologin and sleep mostly. I don't have to enter my password at any time (except when doing root stuff to install programs but not in everyday use). On boot, I do have to enter my disk encryption password.
You can autologin through some options in systemctl, but if you use standard DEs such as Gnome or KDE, there should be an option in the settings.