Yes, more training will invariably give better outcome for a given individual. But some people are just incredibly more talented than others due to genetics alone.

If you want to build an elite sport team, I don't think you want to artificially put less athletic kids for the reason they had to work harder.

I think the question is why do we need elite higher education at all. Maybe we don't. In my view, we want to funnel the brightest people there and make sure they get access to the best resources.