1) Build fully autonomous cars so there are zero deaths from car accidents. This is ~45K deaths/year (just US!) and millions of injuries. Annual economic cost of crashes is $340 billion. Worldwide the toll is 10 - 100x?
2) Put solar on top of all highways.
3) Give money to all farmers to put solar.
4) Build transmission.
And many more ...
The Manhattan Project employed nearly 130,000 people at its peak and cost nearly US$2 billion (equivalent to about $27 billion in 2023): https://en.wikipedia.org/wiki/Manhattan_Project
The relative complexity of projects only ever increases, because if they were simpler we would already have done them. The modern LHC is far more complicated then the Manhattan project. So is ITER. Hell, the US military's logistics chain is more complicated then the Manhattan project.
The fundamental attribution error here is going "look the power to destroy a city was so much cheaper!"
...on their roofs? Over all their crops? What's the play here?