As a Wisconsin Parent, (tax payer and have a kid starting school in September) I can tell you I have an easy answer to this problem.

Give the teachers a raise, hold a certain amount of their pay as performance based and make the school year round (like a real job), with trimesters. If the kids are learning all year long, they have a better chance of getting better grades and getting the info to sink in. Also, parents would not have to pay for summer camps and other BS because our school system thinks everyone lives on a farm and needs to do summer farm work BS. How to pay for it? My taxes will go up. Guess what? They will anyway, at least this way everyone involved would get something out of it.

I can count all of the "great" teachers I had on one hand, the rest of them could have been replaced by robots. Besides, teaching was one of those "noble" professions that weren't supposed to make much money.

When I was a pizza guy, I didn't tell the owner to pay me $40 an hour or else me and all the other pizza makers would strike/call in sick. I took the job while I needed it until I found something better. If teachers don't like their deal, they are free to move on to a real job. One with a retirement account that you have to fund yourself and pay for your own healthcare, because that is how it is in the real world.