"Easily approachable" doesn't mean I can just go ahead do it. It means I can see how one would start working on it, and in fact many people are.

In fact, I am currently working in a nanotech lab, so I am hopefully helping a bit ;)

None of the problems you linked to are things that need to take a hundred years to solve. It's probably more accurate to measure development barriers in R&D costs than years. At the very least, we could just reverse engineer biology.