Seems like Piped and Invidious are both on their last legs. Public instances on both services are pretty iffy, they go down fairly often now. Freetube works well on desktop but no real way to sync subscriptions and watch history to a phone. Self-hosting Piped/Invidious might be the solution but I don’t know if it’s worth the upkeep when YouTube is actively fighting against it.
To add on that: There is (an actively developed NewPipe fork)[https://github.com/polymorphicshade/NewPipe] that extends the functionality with SponsorBlock. LibreTube (another FLOSS app) also has this, Piped support and even DeArrow Support (vs cringe thumbnails.)