All kids can learn something.
The extent of their learning is affected their environment and their natural capacity to learn.
Not everyone can be an astronaut.
Of course not, and I never implied it. What a useless world that would be.
I do understand what you're saying about schools, and I think it's crying shame that academic skill has become so highly prized over practical skill, producing a plethora of university graduates with useless degrees, and no one who can work as a plumber reliably, not to mention the immense snobbery attached to those with book learning over those with practical ability. I wasn't thinking of a school project necessarily. There are other places where kids can learn. If schools are becoming rubbish, maybe other people have to take over.
Saying "That'll fall flat because they don't know things" seems silly, when 'that' might be a project to teach them those things. Like saying there's no point in learning French because you don't speak French.