[TeMPOraL]

The problem was that the science behind those fancy power plants of yours is so complicated, the rest of the galaxy found it easier to just oxidize biomass, and are now scouring every known sector for M-class planets they haven't yet strip-mined from all organic matter.

I say was, because the current problem is that those "environmentalists" you mentioned managed to scare remaining interstellar governments away from this technology, which made them double down on biomass extraction.