A kid is in middle school or high school or whatever and then 20 years later they are on an employer's doorstep. The tools and technologies that employer uses were not even invented when that kid was in middle or high school. Well, unless that kid's had some additional training in those intervening years, they're probably not going to know how to use the tools that the employer wants them to use. So it's appropriate for the employer to hire, instead, the kid who has had the training during those intervening years.
We currently call most of that training "college". If you want to call it "university", or "post high school", or "adult campus learning", or whatever, then do that if it makes it a bit more palatable. Call it whatever you like, but employers kind of need these kids to have it. And they'll only need them to have it more in the future. That's just the nature of our ever advancing society. That's actually a good thing believe it or not.
At the same time, employers will just have to train employees on the specific technologies and tools they need them to use in practice, rather than offloading the burden to society at large.
This also ameliorates the 'retraining' problem for older workers.
Efficient processes measure outputs/results, like what people actually learn or accomplish after all that time.
But many people in this thread are measuring inputs, like, just put in four more years of time and money and that must be good for everyone, right?
That's kind of asking the impossible. Innovation and advancement don't stand still like that. A middle or high school should not be faulted for not knowing what technologies will be in use in 20 years. Quite literally, they can't teach technologies that have not been invented yet. So, again, they pursue the only practical strategy available to them, they teach a general course of study that gives students the ability to absorb and understand what future trainers will teach them. They can't do job training because they literally have no idea what kind of good jobs will be out there when this kid turns 30.
Just make sure the kid is able to absorb the training whatever boss s/he has gives him/her. That's about the best the schools can do. Employers and college really do have to do the rest.