Things were great when I first joined Lemmy a year ago -- it truly felt like a community -- but then unfortunately some of the same toxic Reddit-like behavior started to creep in.
I've since learned that if I avoid the two largest Lemmy instances, plus some of the more sketchy ones like Beehaw and Hexbear, for the most part it's good.
I had a Hexbear account for about a month, and noticed whenever I logged in or refreshed the webpage that someone else's username would momentarily appear at the top right of my desktop screen where mine would normally be, and then mine would appear.
This had never happened with any of my user accounts in other instances, and I was considering deleting it out of fear that my username (and, perhaps, login credentials) might somehow get compromised.
Anyway, I ended up deleting it for something else -- the very same reasons often mentioned in the comments here, after experiencing some of that toxic shit firsthand. Good riddance!