lemmit.online ?

It's a single bot, block it and it's all gone.

Sort of makes sense, if you go to their home page their description is

A Reddit to Lemmy crossposting instance.

So the entire instance is just bots re-posting content from Reddit.

I don't normally browse /all so haven't seen the posts myself. The Lemmy web ui doesn't allow blocking instances so you'd just need to block the bot for now. I've read that some apps can do instance blocking.

Yea, it's not very good. Don't subscribe to any lemmit communites. I don't think you can block them from Lemmy if you use /all.