Economic growth is probably near its current maximum because humans remain a key bottleneck in labor, discovery, and productivity growth, and machines cannot readily substitute for them given their complementarity with capital.

“can't be much faster than this today like it's probably about as fast right now just because humans are such an important bottleneck they both supply the labor they play crucial roles in the process of like discovery of various kinds of productivity growth there's just strong complementarity to some extent with capital that you can't substitute machines and so on for humans very well so the growth of the economy and growth productivity just ends up being bottlenecks”