those electric chairs you have in the US for the near-terminally fat
wait, is obesity attracting the death penalty in the US now? Not before time, I say. I've heard that the obesity problem in the States is the reason magentic north and geographic north don't line up.

If they came up with a split plumbing system that divided my drinking water from my poop and shower water, I would be fine
That's the idea and these systems already exist (it's not exactly complicated to do). The problem is there's no real motivation for builders to include them in new builds and retro-fitting them is very expensive (you have to replace the whole plumbing system) so existing home owners are unlikely to adopt them. If we want to see large scale uptake of them (and I think it would be a good thing) then government is going to need to incentivise them.