This was a problem with Reddit that Lemmy never attempted to solve: you piss one person off (maybe not even through any fault of your own) and rather than just block you, they ban you from every community they moderate.
However, Reddit didn't really have a solution to that. Lemmy kind of does: you can make any community you want, and communities that pull crap like this might be avoided by users who don't tolerate that kind of thing. Or they might not, but the users have more power here.
One thing Reddit was good for was, one mod would make communities like, say, "iPhone 16," "iPhone 17," "iPhone 18," and so on up to like 50, and then lock them until that phone was announced. Same with game series, movie franchises etc. Then when people opened rival communities, they would brigade them, harass them, post things there with dummy accounts that would violate Reddit rules and get the community banned, stuff like that.
Lemmy isn't going to fix all of Reddit's problems because Lemmy is trying to be an alternative to Reddit, which means the more people Reddit pisses off, the more of them are going to end up here and most of them are going to do the same shit here that they did there. And until people show them that that behaviour will not be tolerated... they're just gonna keep doing it.