Honestly I'd start looking for ssf/tiny PCs being sold off by local businesses. I'd be putting some sort of Linux distro on it. I've been meaning to check out a few projects like KDE Big Screen and others. Unless there is some sort of killer Android app you can't live without.
OP did not specify what services they were using. I assumed if they were interested in tinkering with this sort of thing, they probably host something like Plex or jellyfin.
What is the reasoning behind this suggestion? im ok with that but its not really the same thing to normal people (theyre using built in smarttv ad hellscape atm)
Are you suggesting that because price or because what I'm asking about doesn't exist the way I'm imagining?
The reason is choice and support. On an arm android device you have to wait for the manufacturer for updates or to publish source, so someone can support the device for you. With x86 it's just a normal, standard pc, you can do whatever you want.
Usually you can have 3 kind of rom for an android device:
Default from manufactuerer: usually locked down, shitty default apps and preinstalled crapware, updates stop soon. Usually stable.
Cooked/unofficial rom from xda or telegram: some script kiddy has the same phone as you and they share the rom they built from source. Hit or miss, sometimes very good, sometimes terrible. Updates stop when script kiddy gets a new phone.
Official 3rd party rom, Lineage is the most common, Crdroid, Graphene, eos and other secure and special roms are in this category, but they support far less devices. Updates are automatic, built by a server every month. Someone have to set it up, so you still need someone interested about this in the community, and the manufacturer have to release drivers, firmware. (They should be legally, but noone cares) Usually that's the best experience you can get on an Android device nowadays