Burn it? With all the talk of carbon capture? Recall that plastic literally consists of a mass of hydrocarbons. Why not bury it?
I'd argue that if we are burning plastics we get to dodge microplastics, and we get a second use of hydrocarbons. Burn enough plastic, maybe we can displace some gas. Optimistic, I realise.
I think the legitimate answer was groundwater contamination, but that should be solved for other things we bury. I'm on board for non-biodegradable plastic trash sequestration