The unfortunate reality of the internet is that anonymity is abused by troll farms and genuine human interaction is corrupted by their astroturfing and political propaganda. Anonymity in the hands of the powerful is so much more corrupting than the liberty it imparts to the weak.
Shills don't need anonymity. They can troll and astroturf just fine under their real names, or the names of the people they're paying to shill for them, because there is no one who comes in the night to put a bag over your head for shilling for the establishment.
The people who need anonymity are the people who would be punished for saying things people in power don't like.
>Anonymity in the hands of the powerful is so much more corrupting than the liberty it imparts to the weak.
Even if it were so, it is still a win. Without anonymity there is no liberty to the weak at all. And thus for that liberty we must endure all the crap.
Bots are only an issue for public posts, not chat groups and DMs where the most valuable interactions happen. Ideally chats would be encrypted, untraceable, and anonymous, except to the people you're talking to. Anonymity is an overwhelmingly positive feature there.
For public feeds, you seem to assume that only the propagandists can leverage bots effectively, which is the right assumption for the centrally-controlled social media platforms of today. But if we make a platform that is just some protocols that can't be controlled by anyone, you and I would be able to spin up anti-propaganda bots to pwn the propaganda bots without fear of repercussion. Anyone can try to push public opinion in a specific direction, but someone else will simply go the opposite way. There would be no moderator or algorithm to artificially boost one type of noise over another, so we would actually get a less corrupted feed that accurately represents what people are thinking because the noise cancels eachother out. And if you want to customize the feed, we could make client-side filters and algorithms. There could be an open-source algorithm called "Hacker News" that you can just download and install into your open-source social media client.
As for keeping the powerful in check, don't forget that we've kind of lost equality before the law at this point, as shown by the Epstein saga. If we try to remove anonymity from the Internet right now, it will only be used to surveil regular citizens but not the people we need to keep in check. I would happily support a law that selectively enforces the other way around, though: let's mandate real identity for all government personnel online and expose their Polymarket accounts.