You mean https://en.wikipedia.org/wiki/Incineration?

At family gatherings here it's a typical argument for why there's allegedly no point separating out plastics: the recycling bin allegedly also ends up there. Nobody ever has a source for me though so take that for what it's worth, but it seems to generally be a thing

TIL incineration can involve power generation. I am familiar with the term, but had assumed incineration was basically endothermic and wasteful.