I got burned once when my company did a annual employee survey. My boss determined who gave the anonymous answer and fired me eventually.
People who provide negative feedback on these surveys do become targets, and not always for retaliation, but because companies (or the subgroups inside them) don't want discontent to spread, or would rather have an unquestioning happy employee they can manipulate.
It made a very nice Batman shadow on the manager’s dashboard. That’s about all they can be used for.
…which is a pretty good proof of team cohesion.