Well, it's unfortunate that so many students think that school is a waste of time, so I think it's a good thing that the government mandates that one stays in school. It's for their own good, although many young folk don't agree. But I can't discount those who prefer to enter the trades, such as electrician or plumber. We need those folks since that kind of work can't be offshored.
You don't want NEET kids at 16. But it's silly, unproductive and disruptive to keep kids who aren't academically-inclined in an academic setting by that age. Education is never one-size-fits-all. So they need a range of options at circa 16: vocational training, apprenticeships, non-academic courses, &c.
And, sure, if they can get themselves a job at that age, they can circumvent even that. Hell, if they can make an income from reacting to movies on YouTube at that age, you should probably leave them to it. But if their job goes pear-shaped, they should be allowed back into the system.
So: end mandatory education at 16, but offer extensive alternative support until 18 rather than just kicking kids out of the building and rubbing your hands clean of them.
theres a brand ranges of intelligences. the kid who makes a good psychologist has different ones than a mathematician or mechanic. its a weakness of the educational system, teaching styles and underfunding.
in grade 10 I had a 53 in math. in grade 11 I had an 89. the grade 11 teacher actually understood how to teach.