Anyone who’s been using privacy-respecting frontends for some time will recognise Piped. A YouTube frontend with no ads, integrated SponsorBlock, return dislikes, and a customisable UI.
Piped also allows you to subscribe to as many channels as you want without ever logging into a Google account. You can export your subs list from YouTube and import them to Piped seamlessly.
If you’ve never heard of it, give it a glance at https://piped.video. For more instances, check here.
Do any of these frontends have a “watch later” function? What I really need is the “remove watched” button, since its just a playlist.
I just create a playlist “watch later” add my videos to it and use it like the watch later feature in YouTube. It does a pretty good job