I've long wondered what technological advancements would be necessary to make it profitable to mine landfills. There's so much raw material buried in one place.
It's already profitable, or at least net-zero, it's just not politically correct. Here in Minneapolis (more generally: Hennepin county) we industrially incinerate our trash. The site lists many benefits: https://www.hennepin.us/your-government/facilities/hennepin-...