I suspect you are cherry-picking. Not that your observations are wrong, but your validating kids seems like something that is very important a set of kids that I could see someone having a job dealing with, but that doesn't mean all kids need that - the set that doesn't isn't the set you will be working with.
> A school where they aren't allowed to learn about what they are interested in, and can only learn the government-mandated testable knowledge
We need to be careful here. While kids should have some opportunities for what they are interested in, the world doesn't need many professional video game or sport players. We need to force kids who are really interested in some things to learn skills that the world will need once they grow up. We are not in a "post scarcity" world, and there is no reason to think we will be, so they need to learn useful skills to contribute to society. It doesn't take long to teach someone to run a pick-axe (assuming they are physically able and we don't care much about safety) - but glad the world needs skills that are much harder to learn.
The kids I worked with were engaged in an entertainment opportunity, rather than some kind of mentorship for troubled youths, or scholarship. I worked with posh little kiddos and literal charity cases (kids enrolled via charity organizations) and everything in between. Some kids were "forced" to be there, some kids weren't. Some kids were physically healthy, some kids were ailed.
I won't belabor the point, but while I will always provide for bias in my consideration, my sample subjects are the absolute least of my concerns. It was a wide enough variety, and I've compared it to enough adult-oriented psychoanalytical literature, that I feel comfortable speaking confidently about it.
As far as needing to be careful, I agree! We should ALWAYS be careful when doing things in the interest of other people and children especially. I fully support mandatory learning because even aside from practical skills, an ignorant populace is empirically more likely to foment and tolerate a fascist government. I think kids should be forced to learn all kinds of things, and a much wider variety of things than we currently teach. Where I make the distinction is that I think they should also be ALLOWED to learn the things they WANT to learn. By which I mean we shouldn't just tolerate it, we should make explicit space for it. Whatever it is. And that can be distasteful to a lot of people, but the situation - now - is that a kid CAN learn about anything they want to learn about, via the internet, so your option is to facilitate that curiosity into either satisfied disinterest or an upstanding pursuit, or to calcify it as a taboo.
It may be audacious to talk to kids in graphic or sensational terms about violence, but when their school getting shot up is a real daily possibility, it's disingenuous to NOT talk about it. THEY will be talking about it. So when YOU don't talk about it, they can feel how artificial it seems, just like anyone else.
So, yes: learn arithmetic, so you can learn algebra, so you can learn geometry, so you can learn physics. But if we have to cut chemistry to make room for some individual learning time, let's do it. Shove the practical parts of it into a cooking class and leave anything more complex to higher or elective ed.
> A school where they aren't allowed to learn about what they are interested in, and can only learn the government-mandated testable knowledge
We need to be careful here. While kids should have some opportunities for what they are interested in, the world doesn't need many professional video game or sport players. We need to force kids who are really interested in some things to learn skills that the world will need once they grow up. We are not in a "post scarcity" world, and there is no reason to think we will be, so they need to learn useful skills to contribute to society. It doesn't take long to teach someone to run a pick-axe (assuming they are physically able and we don't care much about safety) - but glad the world needs skills that are much harder to learn.