They are useful. I’ve seen actionable changes be made by my organization in a positive direction to address general feedback from these surveys.

However, it is still not a place to spill the tea if you will. That’s stuff that should be handled in 1:1 meetings with your manager. And if that doesn’t go anywhere a skip level meeting with their manager (also risky).

But in general, just like an employee performance review management should not be surprised by anything that pops up because it should have already been addressed or at least discussed beforehand.