Don't forget NewPipe for Android, Yattee for Apple devices, SmartTube for most Android TV boxes, Playlet for Roku, and Invidious for PC (if you don't like Piped).
The only (usable) platform I can think of without a ad-free YouTube client is maybe webOS for LG TVs.
(some of these clients are also missing some features because they are new, but they should all be better for watching than the official app)