I am a teacher who quit -- this article covers much of my reasons, not all, but i suggest you read the whole thing.

Other reasons not covered include government laws for testing -- I equate this to congress passing law that doctors must do brain surgery with an axe and chain saw and nothing else.

The over sized administration, money sucking top heavy entity of the public school that does nothing but eat money. The idea that the school is there to mix children in some sort of social soup instead of educate them -- which leads to hemorrhaging money in bus programs.

There are other problems with public schools.

I have finished with teaching too. Call it a breakdown. That happened because I made the mistake of wanting the best for my classes and couldn't cope with the politicians and their lack of interest in schools.
Trouble is, the attitude has been more or less the same for the last 2000 years.
If Unions try to make the job more attractive, the govt bashes them.
Interestingly, most past students I have spoken to never considered teaching because of what they saw in schools. Now Universities have again lowered the level of entrance qualifications. The same attitude to nurses and police is resulting in similar problems.