I am not sure this will do what I think it is designed to do. The current problem is, for example, people who are not confident enough to ask for more money being paid consistently less than others who are doing the same job. These people are likely to be female and/or from a minority group.

The problem is, if you haven't noticed yet, that it might work for a low/semi-skilled job like e.g an estate agent "£25-30K + £10K OTE bonus depending on experience". But it doesn't work for artistic or highly bespoke jobs like doctors, lawyers, some types of engineers etc. where the salary range can be much larger. Does it really help anyone to say, "Wanted: Software Engineers. Salary £25-100K depending on experience and skill"? Lots of ads already show that, people might think they are worth near the top end and get low-balled with an offer (fairly or unfairly) whereas the people who are not confident are still likely to get paid less money.

As for telling everyone what everyone is paid, that opens even more cans of worms. It is not always easy to describe that the other person gets paid £10K more than you because they have e.g. "a better attitude" (says who?), "is more productive" (based on what?) etc. and tbh, it is not usually completely objective.

Sometimes ignorance is bliss. If you are all about money, then ask for what you think you are worth and if you don't get it, move jobs. I think what other people get paid should be nothing to do with you.