You found the right place to post, I'll give you that.
You've made some assumptions:
like nothing worthwhile is learned by anyone in the latter grades, or rather anything you need to know is finished by 10th.
that schools aren't already rushing through things as it is so if two grades are removed something more will be cut out to make up for lost time.
all kids have a household that is open to that arraignment - and before you say it's the law, I don't know if that's true, if it's everywhere, and if it matters if the law isn't enforced. Some kids will get kicked out, threatened for money, all sorts of less ideal situations.
there's room in the market for more minimum wage people. you're now flooding the low wage market with lots of kids, which is already a problem with ones who are just part time or casual labor.
having a kid stop education and then jump back in a few years later can be a setback to their motivation or vision of their future. I'm actually a fan of figuring out if a high school graduate might do better working a bit and maturing if they don't have ideas, but others thrown into retail or warehouse or office might get the idea that maybe this is good enough and why go back to school.
those total wages are funny. Are you assuming a 40 hour week for a 16 year old? Do you know how businesses actually plan out their labor? With so many kids competing, if they all manage to get a job they'll each have 5-10 hours a week. Maybe.
The only thing that I can agree with you in principle is that not every kid should go straight into higher learning, but that takes some evaluation to figure out the best path for each one. And I guess in some aspect I can agree that not as much is learned in school (not necessarily just high school) that could be, but cutting some grades is the totally wrong way to fix that. Even back when schools were better, so many kids went from high school right into college taking remedial courses so they would be at the right level of education. Less grades isn't going to fix that at all.
It's just not the disruptor it's advertised to be (smart AI that is better than ten employees). The fact that it's being shoved into everyone's faces and threatening or actually replacing people's jobs (inadequately or not) means it is a very large disruptor. Fixing the mess left if we ever get a chance to get back in control is going to be fun.
And it's not just LLMs. The whole everything-in-a-cloud shit, the constant monitoring of clicks to determine productivity, the forced obsolescence of working equipment for new crap that doesn't. We hit a peak in tech quality some time ago, the LLM factor is just another thing on the pile of junk.