>Now teachers in my state make more than an average BS degree and work 9 months of the year...along with better medical and retirement benefits. They still claim they are underpaid
They are. A few years ago I still thought they were oeverpaid and then I married a teacher. She's absolutely underpaid. It is very much not a 9-5 job and, that time off during the summer - some of it get used for required continued education and a good deal of it makes up for the fact that teachers generally don't have vacation time remotely comparable to most other industries.
My wife wakes up and goes to school about 2 hours before classes start. She comes home, makes us dinner, then sits on the couch all evening watching tv while she answers student and parent emails, works on her lesson plan for the next few days/weeks, grades papers, tries to figure out how to squeeze kids in around others during her prep hour or before/after school that are requesting help, find time to squeeze in phone calls during those same time slots with parents that are unhappy with a student's grade or want help for their child.
The weekends are more of the same, a lot of grading/lesson planning/creating content for teaching.
This summer she had 2 weeks of full-time college classes in the middle of summer to keep up with her continued education requirements which required her to purchase about a dozen books that weren't textbooks for the class and required a few binders, several papers, then a 20-page paper. Then weeks before the school year started she had to go start prepping her classroom, attending meetings in person, etc.
Just look at babysitting rates. If you look at the cost of daycare and consider any k-12 child at babysitting rates, teachers are extremely underpaid. Last school year she had roughly 185 students she saw daily. So, the average rate for a local babysitter in Indianapolis, IN is $12.75 per hour as of January 2021 according to Care.com's data.
Assume she had each student for 60 minutes a day - as a babysitter she should have earned $2,358.75 a day if my math is right. She was doing a lot more than babysitting, after marrying her I fully joined the stance that teachers are horribly underpaid.