There is a lot of technical work to turning an invention into an affordable and dependable product.

In fact, I would wager the majority of engineering/math/physics/etc happens after the proof of concept phase.

In that case, Tesla would have lived and died happier if he'd had a Musk around to help him find a way to scalably and sustainably bring what he invented to the world.

You are right. Maybe Edison would be a better example.