Lemmy has a lot of work that needs to go into it in order to handle very large instances like this one. Fortunately the community seems to be patient, but these issues won't go away overnight.
So the answer to your question is yes... for now. But they'll fix it. Reddit had the same issues early on and they fixed it.
Most of them are either admins (read: global moderators to enforce site wide policy) and "community builders" that spam subreddits with reposts and junk to boost activity. Some of that spam was malicious bots of course, but a lot was also from reddit themselves. That's why the site appears as active as it is with so many content creators leaving.
This being Lemmy I expected the picture to actually be a naked person until I noticed what community it was posted to.