Know what 4% annual growth looked like from the 40s to the 70s? We doubled Americans' quality of life every 18 years - by building impossible things. The Hoover Dam? "Too big, too expensive." The Interstate Highway System? "Economically unfeasible." California's entire water system? "The requirements are insane!" They all got built anyway.
You're missing that there could be three hundred million more people working on this. That's a lot of clever Americans who could be solving water engineering and energy problems instead of writing HN comments about why it's too hard.
Don't be another NIMBY sad sack who's been rationalizing American decline since 1969. We used to build impossible things that transformed how people lived. Now we write elegant essays about why new infrastructure can't work, citing books about how hard the old infrastructure was to build - infrastructure we somehow built anyway.
Want that back? Stop listing why it's impossible and start asking how we do it anyway.