Love love love to see so many people participating in the boycott!! Here are my faves:
ihavenotv.com is a curated list of free documentaries! Lots of interesting stuff here!
I'd like to second archive.org, and specifically shine a light on the
Mirrortube collection! Has almost a million archived YouTube videos in it alone! I suggest searching up your favorite creators (by using the term
creator:"CreatorsUsername") rather than browsing it blindly, though. There's a lot of rather odd or uncomfortable stuff.
Itch.io has a
lot of free or cheap indie games for you to play to your heart's content!
Yume Nikki Online lets you play multiplayer online Yume Nikki and Yume Nikki fangames, with no registration required.
If you use YouTube for mostly gaming-related content, Twitch is a good place to turn to!
noises.online is good for those who used YouTube for noises to fall asleep to! Very customizable.
Lastly,
Preservetube is absolutely something worth looking into. Not only can you archive a YouTube video or YouTube channel with just the URL, but you can also search existing archives for a video this way, too. I do not know if this website gives YouTube traffic when it archives, so I'd recommend not using it for at least the first day of the boycott (August 13th), but, past that, giving YouTube one ping to save a video for you and others to watch as many times over as you'd like (thus preventing tons more traffic) is worth it, in my opinion. It's much easier to use and to navigate than the Internet Archive, so, if you're intimidated by archive.org, consider looking at this site.
If you're going past August 13th, and will continue the boycott until the AI is announced to have a rollback, please remember that this is a marathon, not a race! If you feel like you will be unable to stay away from YouTube, setting significant limits on how much you use it is great. I'm putting aside one hour per day to go on YouTube, past the 13th (when I usually spend around 8 hours a day listening to YouTube videos (yes, I know.)), and I will be exclusively using that time to archive videos for off-YouTube viewing.
Keep it up, y'all!