That 40% investment used to be sitting in giant cash slushfunds on company balance sheets. This isn't government investment. It would have never been spent on 'infrastructure'.
On the upside, even if AI is a bubble and implodes spectacularly we're going to have metric tons of compute available for climate models, drug discovery and anything else that requires a super computer to model.
Will we? The hardware you want for AI and the hardware you want for super computing seem to have different priorities, e.g. concerning floating point precision.
compute is compute, yes. Maybe some older models might have to be rewritten to take advantage of a gpu farm's parallel processing capabilities, but humanity will ultimately benefit if the current AI boom fizzles
On the upside, even if AI is a bubble and implodes spectacularly we're going to have metric tons of compute available for climate models, drug discovery and anything else that requires a super computer to model.