You're never truly 100% anonymous online, also anonymous platforms are usually broadcast type. Meaning single users broadcast things to a possibly infinite number of receivers, usually it's even public with no access restrictions.

And me personally I'm much more likely to tell people personal or private stuff after we both got to know our real identities. It's a matter of trust, knowing someone's identity is a sign of trust or mutual accountability. If stuff ever got out, I know who it was that leaked it and thus they get never talked to again. And both parties knowing who knows what prevents them from leaking, because both want the relationship to last (until they don't and that's when the tea gets spilled, or not if both people hold each others tea hostage. Game theory aside, I don't spill tea because of morals anyway).

Whereas I don't really know who it is I am talking to in an anonymous or pseudo-anonymous environment or the number of people reading or listening to it, that seems highly risky to me. If anything it gives me much less control over my private stories and infofmation.

This does not mean I will tell every person I know the real identitiy of everything, of course. But if you want to get to know me personally I want to know your name first and you should know mine as well. Me telling a secret to an anonymous "crowd" though? That will never happen, or ideally it shouldn't. If it does, it's because I don't consider it something I would hide anyway.

Same goes with disclosing corporate secrets and things like that. I would never do that anonymously. First of all, me showing this special knowledge most likely makes me identifiable anyway, so I would need to trust the recipients no matter what. And if they are anonymous as well like when I use Twitter to address some workplace issues, this could come back to haunt me, who knows who's listening, I certainly don't. Secondly I don't see the point in spilling the beans if it's not related to whistle blowing and criminal investigation, and in that case I would forward the relevant information to the authorities or journalists first.

There're so many data points that make you identifiable even when truly anonymous, eg using a non-existant better version of Tor. The vocabulary you use, your spelling and grammar mistakes, references to geography, special knowledge, or expressing idiosyncratic ideas and viewpoints etc. I've analyzed language before to identify a manipulative sock puppet. It was so easy. And even disclosing this fact about myself is another data point that would make me more identifiable if the right people read this post.

You can ask yourself. If you showed your friends and coworkers a link to a Hacker News thread and gave them the challenge to identify your posts (assuming they don't know your user name here), how likely would it be for them to identify you? How successful would a specially trained AI be? Nobody is anonymous, so the people who are telling themselves they can be more open when they are anonymous are fooling themselves. I hypothesize that those who are open anonymously and say for instance hateful and controversial things, have a tendency to say those things in person or under their real identity as well. Maybe not in front of authorities though.