There's a homebrew scene for WebOS TVs: https://www.webosbrew.org/ I don't know of any for Android, but rooting is quite common.

I have that on my LG tv but it's kinda pointless, it doesn't remove the adware from the home screen and hunting the ip addresses down it connects to is a pain in the ass so the tried and tested method was to not give it Internet access

As long as they haven’t done HAB. And provided you’re willing to live with 720p resolution for all your video streams.