Communities disperse, and are drawn to solutions that make them a little trickier to bot into and be absorbed by the marketing apparatus. A little friction that makes it harder for sock puppets / gpt bots carpet bombing your communities wholesale is an ephemeral competitive advantage right now. Not a perfect defense, but what is anymore? Is it even possible to build an effective captcha now?
Tell you what would really gum them up, make some communities require people buy a physical X$ RSA token. Sure you could make bots for that, but how long to automate the unboxing of those tokens? It could become an arms race where the packaging becomes the captcha.
Some humans are going to always try to keep moving ahead of the noise wavefront. I'm rooting for them.
Wanting all things to be index-able these days kind of feels like asking early 90's internet kids to be normal and go hang out at the mall.
Not all human discussion can happen in forum-like format. Quick disposable chats are also usefull for when you're in a state of "figuring things out" where quick and short feedback help you navigate a problem rather than reading long well-researched well-formatted replies.
There must be room for both modes: the "thinking about it now" is in chat and the "having thought about it" is in SO, forums, documentation etc etc.
Or so I've heard.