I'm quite certain that reddit has millions of bot accounts that repost old content and leverage AI to make human sounding comments. They serve two purposes, to simulate activity and interaction, and to disrupt discussions that reddit doesn't approve of, such as those about Lemmy or certain political issues.

Why wouldn't they? It's a very simple decision for them, they need to protect their money and the shareholders money, and they'll do whatever they have to in order to accomplish that objective.