Lots of good comments here already. Let me add my two cents. Plastic recycling could work, it would require two very big changes:

1. We need to produce a LOT less gasoline. Plastic is made from the waste product of making gas. Make less gas, and the supply to make plastics decreases. Right now gas companies basically give the plastic feed stock away for free because they have so much of it. Recycled plastic cannot compete at that price point.

2. We (America, don’t know about other countries) need a MUCH better system to identify and separate our different plastics after consumer use. PETE (recycle code 1) is completely different than PVC (recycle code 3) which is completely different than PS (recycle code 6). But most Americans just see the recycle symbol & toss their plastic thing in the recycling bin. There’s still no good way to separate these different plastics from each other, which you have to do if you want to melt it down & reuse it for new widgets. The little symbols are too small to read or even notice most of the time. We would need to standardize these in a way that would allow auto-sorting at a factory level.