Earlier quoted context omitted.
As far as I can tell, ublock origin still works without a hitch, so just hook up a laptop/ tower to the TV and run YT in a browser?
When casting to the TV you get ads, even though you don't in the browser! I just tried it, since I had the same idea.
Buy an air mouse/keyboard to control it from your couch.
Here's an example: https://www.amazon.com/Wireless-Keyboard-W1-Multifunctional-...
The flexible sovereign combo of a general purpose computer and a user agent.
I use a forever-docked ThinkPad x230 under my TV, which can do 1080p and 802.11n (5GHz).