Some of that may well be real, but one issue that is a factor is that it appears that someone is having bots auto-creating accounts at lemmy instances with open-sign-up, which is believed to be responsible for a considerable portion of the new accounts (basically, many of the accounts don't appear to be active, and apparently the instance admins are banning a number of them). The lemmy.dbzer0.com instance admin has something up on GitHub to try to monitor the situation:

https://github.com/db0/lemmy-overseer

I'll add that that does highlight the fact that the Reddit team has put a lot of time over the years into countering bad actors, spammers and the like, and some of those are probably going to try to hit lemmy/kbin.