You are your own algorithm. If you see a lot of propaganda or whatever, it's because you chose that content at one point or another. And you can just as easily stop seeing it by unfollowing and blocking.

Also, evidence. I see no signs of rampant propaganda on the fediverse, not on Lemmy or on Mastodon. Now, that doesn't mean it doesn't exist. But that's where you should provide examples so I can check for myself.