One side effect of using real estate prices to segregate based on demographics is some districts are very pleasant to work in and high paying and some are very unpleasant and often not as high paying. The kind of kids where Dad make sure the homework is done vs the kind of kids where there is no Dad but you get to wear a bullet proof vest. Dumping money into a district results in administrators soaking it up and no change in results. The only thing that changes results is demographic changes.
The teachers are segregated as much as the kids, such that the PHD in math with 30 yrs experience and a fat paycheck did a good job teaching my high school calculus class, and teachers of somewhat lesser quality are stuck wearing bullet proof vests and having their cars vandalized and stolen. Simultaneously, inside individual districts something akin to communism reigns where the union enforces strict salary discipline based on skill and experience. Its between districts where things get competitive.
Schools are run locally but regulated at state level. My SiL can run her classroom as the locals and her agree, but to renew her state teaching license every couple years she needs X continuing education units per year and her coworkers run the entire range of ant and grasshopper mentality. Its a classic confusion of butts-in-seat with productivity or confusing panic'd last minute cramming with productive effort.
If the license lasts five years between renewals, and career attrition is roughly 10% per year, then the tiny minority of teachers who retire as teachers will have renewed roughly 8 times, while simultaneously a huge fraction of people holding a teaching license are leaving the field or have left the field and are therefore not working very hard on CEU to renew. So its simultaneously true the teachers study and prep constantly and that teacher don't study and prep at all, because a very small fraction of survivors need to while a very large fraction will not survive.
The supply of teachers is too high leading to intentional burnout by management, careers that are shorter than the time it takes to pay off the student loans, and unpleasant working conditions because they can and it reliably produces countable beans. There is no contradiction in stating very few entering the field will be successful, while all who are successful enjoy great rewards. Those who have a very long and well paid NBA career will be quite happy about it; simultaneously almost every kid wanting to be a pro basketball player will not have a long well paid career in the field; the situation is the same for teaching.