My big hope with the fediverse is that stuff like that can be contained. lemmy.world is the big instance where most anything goes. If you’re looking for quality curated content, then you’ve got places like beehaw.org. Similar to /r/AskHistorians, but that was always an awkward system. Is /r/AskPlumbers or whatever up to the same standards, or just some rando subreddit? Now, if you find a community like [email protected], then you can explore the other communities on the instance and be reasonably assured that they’re also up to snuff.
Also, I think the memes and other easily-ingestable content is a healthy sign. It draws people to the fediverse, and then they can discover more niche communities that make them stay long-term. The memes aren’t for everyone, but the memes help everyone get good communities.