Generally I’d agree with you, but consider who is going to be paying your social security and Medicare? Those kids when they grow up. Every kid should be able to be educated for free K-12 all we have to do is change how it is funded. Let the parents decide which schools to send their kids to. School choice. Money follows the kids. As long as the school is effective in teaching the basics, that works for the kids.
There are going to be drop-outs, troubled kids et al, but that is what schooling professionals are trained to deal with.
The schools that are good at it will prosper. The employees of the failures will flip burgers to pay for their BA degrees.
This statement fails the logic test. There is no such thing as “free”. Your statement literally says all kids should be educated through the 12th grade and someone else should pay for it. So back to square one. The only people who should pay for schools are parents with kids that need an education. Leave everyone else out of it.