I can't say I agree. Sure, physical construction is kinda slow, but that's just one "outlet" of the wealth of information ASI will bring.

Right now we depend on some human geniuses to bring us intelligent, movie-like robots (which have a software problem, not a hardware one). Imagine having 100 super-human super-geniouses that need 5 minutes to figure out how to do anything. And that's far from only one field that could instantly benefit from the right knowledge

We can manufacture virtually any compound, we just don't know what compounds would magically cure cancer, spinal cord injuries, aging, etc and what compounds would kill you. Formula for antibiotics that can't be beaten? What genes to modify to eradicate all diseases? Imagine if we could have any software imaginable? How to build dream-like VR goggles?

Even in your example, if a company knew for certain how to build a fusion reactor that magically works, you don't think they'd raise 10B$ in a month and hire 20.000 wokers to build it in 6 months?