Employer surveys typically claim to be anonymous, but in reality there are enough identifiable markers for them to make a very good guess at who submitted a particular response. They are usually coded by Department and VP/Director/Manager. That narrows them down sometimes to a very narrow group. At my last company, given the department size I worked in and the fact that I was “managing” the group put a bullseye on any responses...I refused to participate.
That’s why I NEVER complete employer surveys.