I don't see why it would be at all like plastic recycling: plastic "recycling" was never practical because there are too many kinds of plastic and making new plastic is so much cheaper. When the Chinese were buying it they were landfilling most of it in exchange for payments to take it off of our hands. On the other hand, aluminum recycling works very well.

I'm slightly surprised by landfilling plastic. I hear it's pretty high calorie, up to the point of being energy-positive to burn it with filtering out the fumes. Is it just not enough to make this money-positive when accounting for handling?

Some places do have energy and material recovery facilities next to their landfills that try to extract useful metal and useful energy from trash.

I believe Japan does this, but there are dioxins all over the place there.

Dioxins were become problem in 90s so smaller incinerator is banned and now incinerators must run on high temperature (> 800C) for not to emit dioxins. Emissions are also must be measured.

There are plenty of manmade chemicals that don't break down at 800C. For example F-C bonds...

We really ought to be incinerating things at 3000C, but so far we haven't been able to engineer machines to do this without melting themselves...

Of course not every material can be burned but still fine.

IIRC it's not "recycling" at all - they'd just bury the plastic in China instead of here. Much like we've "reduced emissions" by moving all industrial production to China which is almost completely un-regulated in terms of emissions until 2030. It's as though people think that atmospheric emissions are somehow confined to the country which emits them, rather than affect the entire planet.