Ehh we can go back and forth on semantics all day but I think the point still stands that as long as there is a demand for plastics there will be no phasing out oil.

Do you have a source for this percentage?

We could do a lot of things to save the earth. Action is much harder than hand waiving though. How do "we" go back to glass? Who is we? Who makes this order? How is it enforced? We can say OK we need to shut down all the gas plants and convert to nuclear starting this Wednesday, but that doesn't mean anything because good ideas don't just happen in this world. Business cases happen, and if the idea is a good one its a happy accident. We need to develop a framework where it is more profitable to turn to green choices than alternatives before we can expect the world to wake up and change overnight. And setting up such a system is impossible when indirect action and chaos theory has created the system we currently have today, one too big for anyone to fully understand or shift with a few lever pulls to no other consequence.

You would emit more CO2 switching to glass than you would save. It's not worth it.

Glass is heavy, breakable, and not worth recycling (the planet's crust is made of glass so there's no real reason to recycle it, the glass shards harm the recycling of everything else, and the weight consumes extra energy in transport.)

And yes, you could make plastic directly out of air. And you can recycle the plastic back into air by burning it. It's a very clean process.

If you do the right kind of searches you'll see people are working on using cellulose as a chemical feedstock and for plastics. That sort of research was dead since after WWII until recently.