You’ll need pretty solid justifications to lower salaries. In a case where a bunch of employees realize they’re underpaid, there’s only three natural outcomes:

- lower paid employees don’t get anything, and start looking for a better paying job

- lower paid employees get compensatory raises

- lower paid employees get nothing and the higher paid members are expected to get lower pays. They proceed to leave for greener pastures (and they only need to find at least equal paying jobs to make it worth it)

The scenario where salaries go down and employees don’t do anything is unrealistic.

Have you done an actual survey? I doubt you know the inner workings of every workplace of everyone you know.