Reddit and Twitter are filled to the brim with spambots and remain successful.

Just because it’s where all the users already are. You couldn’t start Reddit today, it’d immediately get spammed by AI bots and no one would stick around.

Hell, Reddit’s API changes had a noticeable impact on most text-only subreddits I was a part of, and then the AI content just made a lot of the remaining ones die off. No one’s rushing to Lemmy to fill those niches. They’re just not participating in them online, instead.