In theory this runs just as well on TVs if the right drivers are present. They ship postmarketOS versions of their firmware, for example.
Sadly, pmOS doesn't support any TVs as far as their website is concerned (https://wiki.postmarketos.org/wiki/TVs) but with some work (getting the mainline kernel to boot based on the GPL sources or getting the built-in kernel to boot pmOS) you can flash your TV with this firmware. In practice you won't be able to do much with it as TV SoCs are almost always shipped with underperforming hardware and as little RAM and storage as possible, but you could.