The key point will be the energy inputs, and catalyst or other process input losses. Not the % recovery, its more recovery at an economically viable cost

Many processes could recover the inputs. Some are tremendously polluting. Cheap methods to recover lead from older lead-acid car batteries would be an example, or the way scavengers burn plastic insulation of recovered copper wiring.

TL;DR exernalities and economics and pollution drive recycling issues, not % recovery at this point. We know how to recover a lot of the inputs. Knowing how to industrialise and scale it up is what counts.

John McCarthy (of LISP fame) was an (in)famous curmudgeon on USENET, frequently used to say future generations will thank us for making giant collections in the ground of highly valuable recoverable industrial inputs, what we call "rubbish dumps" -He was only partially less wrong, but had a point to make about the cost of inputs to industry vs raw mining costs. If we do come up with a process to strip mine rubbish dumps and send feedstocks in the appropriate directions there's a lot there. Complex plastics, Metals, Organics, Acids, Methane Gas, you-name-it. We already collect and harvest the methane to drive other dump works, the idea of mining the materials isn't "wrong" as much as insufficiently economic right now against raw material sources.