I think the key here is that as much as some AI doomsayers don't want it to be the case, and even as much as a lot of people would claim to care, most people won't care enough about whether or not they're consuming AI content or human content to for it to be worthwhile investing all that much effort into stopping automation.

What matters a lot more is to stop abusive behaviour and low quality slop - whether or not that is written by humans or AI.

And working to detect that is a lot more tractable problem than trying to stop automation.