Moderation lists and labellers honestly already get you most of the way there. Labellers are very effective at flagging spam/botted content and accounts that continuously show up on labellers as spam/bot content get referred to moderation lists dedicated to specific types of spam and bot content.

So you can already start by using a labeller and just hiding that content behind a warning (kind of like the NSFW wall), hiding it entirely, or just attaching a visual tag to it (based on preferences). And then to filter out more consistent perpetrators you can rely on mute/block lists.