I see the basic problem as "plastic monomers cost about 50 cents a pound." Exxon-Mobil is happy for chemical recycling systems to break plastics down to "a mix of chemicals you might find in the BTX section of a chemical factory" because those all cost about... 50 cents a pound and are interchangable from that point of view.

Landfilling costs maybe 2 cents a pound, any kind of recycling scheme chemical or mechanical has a hard time beating that.

That said there is some market for mechanical recycling. I've got some nice garmets made from recycled PET bottles, I think the feel of the polyester is better than average. That's no "circular economy" however. In New York you can find PET bottles for Pepsi and Coke company beverages but I know some people who are afraid these will shed more microplastics than virgin bottles.