Concentrate on accounts you follow, and expect to run out of things to look at. Avoid “for you” and “suggested posts/videos” - when you’re out of Following posts, you’re done :)
People have said the internet is full of horrors, and I know that’s true, but I haven’t experienced it. That’s not to brag, just to show it’s possible! And I have spent my time on Tumblr, Reddit, pre-Musk Twitter, YouTube, instagram.
Link goes to a post with specific advice for IG and YouTube. I don’t think Twitter can be used this way anymore, and you will have junk shoved into your feed no matter what.
Maybe start fresh with new accounts to reset everything, too