No sub, on Lemmy or Reddit, is safe from power tripping mods. I’m currently dealing with a Lemmy mod on a few other Lemmy subs that’s abusing his mod powers.

The bottom line is the other mods either need to step in and reign the bad mods in or remove them, or their sub dies. Seen it on Reddit plenty of times. But I’ve also seen Reddit mods that successfully removed their bad actors and then everything was fine. So it could go either way.