Pointless user interaction isn’t really required on lemmy/fediverse/activity pub. Because they don’t have to sell them selves to advertisers. As long as there’s productive conversation and hosting isn’t a burden current instances will likely continue ticking along.

What’s most likely to kill it would be admins being overwhelmed with moderation needs and a general user backlash against moderation actions.

That’s killed so many websites I’ve ran/moderated for, giving too many chances to users who didn’t deserve them.