That "anyone" also includes you, no? Why aren't you doing anything about it?
What you are describing is not a problem of lack of manpower, or productivity. It is socio-political. If it was in the interest of the status quo to actually fix all of these issues in the developing and developed world, then rest assured you'd get a machine that could clean and repair infrastructure in no-time.
Everytime someone says that I look around at the cracks in the sidewalk, the mold in the walls of my house, the empty lots and single family homes in one neighborhood and the OD'ing junkies in the next neighborhood, and I think, if there's less work that needs to be done, then why isn't anyone doing all this work that DOES need doing?