> I don't think it's given that all superconductor breakthroughs will require 40 years to get to that point

Absolutely right. People generally understand that "collective human knowledge[0]" grows but they think of it as a linear system. The speed at which knowledge grows accelerates -- not at an even pace -- but I'd wager somewhere near exponentially in a lot of places.

And each discovery can change our understanding of other things/accelerate discovery in other areas.

[0] So much as such a thing can exist