What's a good waste management system? Honest question.
https://en.m.wikipedia.org/wiki/Plasma_gasification
Unfortunately it's more expensive than just throwing waste into a hole in the ground.
While we still use hydrocarbons for a while for power, we might as well let some of them hang out as our stuff for a bit before being burned for energy.
Sure, small-scale "energy recycling" makes sense, but if everyone did it with all our waste plastic outout then we'd pretty much just be using fossil fuels with extra steps, and the carbon will end up in the atmosphere.
Therefore you get to leave some oil or whatever in the ground instead of going to the trouble of burying garbage.
Burning garbage instead of fossil fuels should be carbon neutral with some benefits of not filling landfills etc.