Even if we don’t eat it, converting the plastics to something biodegradable would be a huge win.
It is not a matter of conversion. most plastics can be recycled or burnt cleanly. It is a matter of collection, sorting and operationg the recycling facilities at an economic rate. The last thing can be done easily. Just introducing a high enough tax on non recycled plastics would do the trick.
As always in capitalism plastic waste is not an issue that lacks technological means. What lacks is the economic and political will to deal with it.
Most plastics cannot be recycled, and produce disproportionately high levels of greenhouse gasses and toxic fumes when burned. Burying plastic in an encased landfill is the best way to dispose of it, otherwise it will end up in the water cycle. If we can feed it to mushrooms or bacteria, the world will get cleaner over time.