I don’t know how their backend works, but as a former db admin, it seems wasteful to maintain that many layers of change for every user. I would certainly do that in a mission-critical system, but for millions of pseudo-anonymous users, many of whom are shitposters, that would be an insane waste of server space.

That may be true, but I would be a bit surprised if there were a change-log like that.

e: keep in mind, systems like this don’t just work like that – you’d have to do extra work to build it that way on purpose. And you’d be doing that extra work, maintenance, and hosting for a user base who aren’t paying you, in a system you’re giving away for free, in Lemmy’s case.