The reason is that people don't want to pay property taxes.
It's not nefarious cabal, it's the fact your neighbors hate paying taxes on their homes and vote down tax increases, such that education has been systematically underfunded for decades.
This started in the 70s. Look up 'property tax revolts'.
Education funding plummeted, so states and the fed were expected to make up the difference, but it only made things worse and worse because their aid packages were tied to standardized testing, lower teacher wages, and etc.
I worked in my local town on the town meetings. the #1 thing that came up every year, was do we raise taxes, or do we cut school funding. They chose to cut funding 80% of the time. year, after year, after year. until the state came in and basically forced them to raise taxes, or lose their aid package. that was the only time they got raised the taxes. my dad lost his fucking shit, even though the increase was only about $150 per year, which was less than his monthly cigarette budget.
Towns with great schools, overwhelmingly have very high priced homes, because that's how they get their money, from the property taxes on those homes. If you can afford a home that's over a million dollars, you likely live in a great school district. If you can only afford a home that's like 200-300K or less, you live in a crappy one.
The tax rates are often lower on the high value homes, because the overall income from those taxes is much higher.
80% of school budgets come from property taxes. the state and fed funding is very limited by comparison, and it's mostly used for capital or other large/sweeping projects like building schools, standardized testing, etc. it doesn't pay teachers or operating costs of the school.
teacher pay also varies wildly by district. teachers in good districts make 2-3x what they do in crappy ones. because they can hoover up all the good teachers and leave the crappy ones in the crappy schools.