Discussions are supposed to go both way. The first way - I learn things - is still valid, maybe even more with the advance of AI. Even if all the contributions I just read were AI generated, I would have liked it. I guess. But the second way - I teach things - get partially destroyed if I lose time interacting with bots. Forums need to be reinvented to provide some sense of trust. I am not sure that's the end of online privacy though, we are smarter than that and we will certainly figure out systems that will ensure a human wrote it without gathering personal informations.

Somewhere else someone pointed out that using AI to reformulate our thoughts while masking our own style is a possible protection for our anonymity considering the kind of threat showed in this post: https://news.ycombinator.com/item?id=33755016 . This should seriously be taken into account.