I can tell you why with reasonable certainty. When my mom became a Maine teacher in 1990, the starting pay was $28k, for a part time position. By her first retirement in 2022, she was making $48k, for full time work, in a more expensive school district, with more responsibilities (including creating the entire lesson plan and running the department). What was inflation during that time frame?
So basically, Maine can't afford any teachers. It's been coasting on the same 65 year old teachers it had back then. The few new teachers you DO get in rural Maine are the ones that aren't smart enough to notice that they're getting fucked, or are morons screaming at 12 year olds that the vaccine is poison and masks will kill them, or are literal sociopaths who write 17 page (not exaggeration) manifestos full of spelling mistakes and grammar errors due to a perceived slight. Despite that man being an obvious wacko, the administration we spend so much on left my mom high and dry to fend for herself, and it could have destroyed her career and reputation as one of the best teachers in the area.
A school in the Kennebunkport area convinced her out of retirement with a cool $80k a year and strong agreements towards getting her (state program) retirement fully funded.
Everyone in the US loves to harp that "oh we've spent so much on education" but we have not. We have spent immensely on paying a bunch of MBAs to "administrate". Superintendents are politicians, and do not do anything useful for schools. That superintendent spent tens of thousands of dollars on "smartboards" while the teachers used VHS tapes bought in the 80s to teach things. Teachers want supplies, not gimmicks.
But don't worry, that Superintendent will use his political connections to assure everyone that the millions a dirt poor community has handed to him totally isn't a waste, and that buying a heated turf soccer field in fucking northern maine wasn't a waste, and the local numbnuts will continue to blame "woke liberals". It definitely has nothing to do with talented teachers who worked their asses off for 40 years getting jack and shit while their bosses drive Mercedes and buy their third house.