And certain services (like Write.as) keep track of all the posts you've written, and they can optionally can be tied to a pseudonym. I don't think that an assurance on who wrote what is always necessary. If the writing is good, the author doesn't necessarily matter. And anecdotally I think people who abuse anonymity online are in the minority -- most people use anonymity to share more candidly where they otherwise feel repressed.
And I think "worth" is best decided by the reader, and a human touch continues to be superior to any technical solutions we've come up with. Platforms who try to uniformly enforce some standard of "worth," in my opinion, risk alienating a large amount of people, and usually miss the entire standard they were going for in the first place.
But what other problems do you think exist with text publishing services? Or what do you think needs to change? How do we solve those things?