But in one episode they are walking along a train line and I can't help but think in 15 years no one thought "hey you know what would work well on this old train line... a freaking steam train". The in the same episode some thinks 'hey lest get some people to pull this helicopter through the jungle like a group of Israelites slaves in the Prince of Egypt'.

Ok so electricity is gone but why has technology regressed to the stone age. Same episode - someone says they can't make bullets any more, didn't we have the ability to make them way before we had hair-dryers.

And everything is overgrown what does that have to do with the power going out. Yes we live a world that requires a lot of power to keep things running and with out there would be a food crisis and lots of death but most of the world did not have power until well into the 20th Century so at worst after an initial correction the western world would settle into an 18th century type economy and technology. They have regressed too far.