If you’re looking for an in-browser alternative I’d highly recommend you take a look at the LibRedirect extension for Firefox and Chromium. It’ll automatically redirect any youtube URL to your preferred alternative between Invidious, Piped, PokeTube, CloudTube, Tubo, FreeTube, or Yattee.
If you’re looking for an external app and like using a Linux terminal then ytfzf may be a good choice. I’ve briefly talked about it here. It will even allow you to search on Youtube (through invidious), Peertube, and Odysee if you so desire.
If looking for a phone app, I personally like NewPipe.
Check disroot https://www.makeuseof.com/tag/disroot-encrypted-email-cloud/