One important option seem to be entirely missing here: Start. A. Union.

It seems the real problem here is the power difference between people, combined with the powerful side not having a thick enough skin… or lacking the actual competence that we ought to expect of their position.

A competent leader will not be offended or feel threatened by a piece of feedback, however negative: either the feedback is crap and they'll calmly say "nope, trust me I know what I'm doing here", or the feedback has enough truth in it for them to say "oops, I'll do better next time", and then proceed to actually do better.

An incompetent leader however likely know they're incompetent, and they're less likely to meaningfully judge feedback. They're more likely to look for social validation, and more importantly secure their position. Any negative feedback threatens that position, and when that feedback comes from below, the solution is obvious: slap the peasant down, perhaps even fire them.

Often there's little you can do around those people. For instance, I once applied for a contracting gig that would involve cryptographic work. I was rejected because I was "more competent than the project lead". My guess is the hiring manager there knew that if they brought in someone more competent than the project lead, things would go bad. Quite the indictment of the project lead if you ask me.

My best project lead on the other hand had no problem being a worse programmer than the people under him (the tech lead for sure, and I probably). He worked on the parts he could, trusted us to do our thing, and I trusted him with telling me the priorities. Best gig of my entire career.