You can use the distributed proof to say that these accounts belong to you. So if you are doubtful about the integrity of a post, you can look up their blockchain ID and find out what have they been doing elsewhere publicly. Additionally, any post that does not attach a blockchain tag or something will simply get filtered out or ignored. This puts every "anonymous" post on the web a weight which it does not have in the age of LLM.

How are you guaranteeing that this ID corresponds to a real human bean? Blockchain seems terrible for this on the basis of complete reliance on an external central authority.

It doesn't but you can always augment your ID by attaching a government ID or some sort. On the internet tho? If you _only_ have texts, there is no feasible way to distinguish a person and a bot.