First, he clearly has no desire to learn.
I disagree. I believe he's learning that for every reason people give him to stay in school, he has a corresponding excuse that negates it.
Which is probably exactly what he wanted to learn: how to argue about this. It's practice.
What to learn how school can affect your life, talk to people who have already gone through school (or didn't) and actually KNOW what it did for them.
There are four things I can put directly into that discussion.
1. I hated school. I got out of it as quickly as possible. I have regretted this decision ever since.
2. I got out of school by slamming through my classes, graduating at 16, going to the cheapest and closest college I could find, and ripping out a worthless two-year degree in a garbage field. That was stupid on every count, but it was not even REMOTELY as stupid as coasting through high school with a crap GPA and simply not going to college.
3. I have not been massively damaged by the stupidity of my choices. I regret them, and I wish I had made different ones, but in the end I have not really suffered professionally - because I make my living doing something I love to do. It is, however, important to recognise that it is not what I wanted to do - I wanted to be a chef; I wasn't good enough. I wanted to be a stand-up comic or a magician; I wasn't good enough. I wanted to be a musician; I wasn't good enough. Instead, I ended up a successful software developer.
4. The ONLY REASON that I have not suffered overly as a result of my educational choices is that I have always, always, ALWAYS educated myself and made backup plans. And amazingly, what I ended up doing - and doing well - was what my parents told me I should be doing. It took me ten years to figure it out for myself, and if I'd just shut up and listened, I'd have gotten to this stage in my career a lot sooner.
So what would have made my life better wasn't school. It was shutting my dumb little teenage mouth and listening to what other people said.
Take that as you will.