Lawyers are a counterexample. There are more law graduates than jobs. But starting salaries haven't gone down.

David Graeber made this observation, and suggested some sort of class tribalism.

Btw, to use cleaning as a specific example, taxation of domestic services is broken in almost every (western?) country and skews how people spend their time and money. Most professionals would happily trade an hour of work for an hour of cleaning services, however, by the time you put income tax (and VAT in my case) on top, your hours need to be about 2.5x times as valuable as your counterparty.