This has to happen in some form, or sites like Stack Overflow will die, and with them, the AI models that rely on them will suffer.

It's less clear with Twitter & Reddit, as the function of those sites is social, not looking up answers, i.e. SO is directly replaced by AI, while Twitter and Reddit are not.

The problem is this means the fragmentation of the Internet. Everything will be behind paywalls soon, because if humans can access it, AI will also access it. Not sure how the endgame looks, but it's apparent now how much of a head start OpenAI has by managing to grab all data it needs out in the open before the shit hit the fan.