These markets are monopsonies. The market rate is much lower than the actual value these jobs are worth. Even so, we do not have enough firefighters and teachers. This is a price signal that the current compensation is insufficient.
Not enough firefighters in that there are open positions and no one is interested? Or open positions only for the already trained/experienced?
If it’s the latter then that’s an argument that compensation is too high if anything. It should be rebalanced such that some of it is used for training.
If the former then that’s just alien to me. Here in Australia firefighting is a prestigious job with a lot of competition. People volunteer to do it for free or do it part time while working another primary job, for years, in the hopes of being able to become a full time firey.
In California, people aren't volunteering enough, they have to resort to prisoners. As far as teachers at least, there are open positions, that require training of course, hence the need for a higher salary.
