There are scripts you can run (there’s a few people have posted on GitHub) that will do one better.

If you mass delete all your posts, Reddit can detect that and just undelete everything. I haven’t seen evidence of that happening, but that’s why people wrote those scripts so maybe there’s something to it.

What those scripts will do is go and edit everything post and comment you’ve ever submitted and replace it with gibberish generated content. That effectively poisons your history in Reddit so the poor AI training runs have a bad time.