How does the USA dispose of its plastic waste?
Almost all clean plastic CAN be recycled, although uses are limited. Plastic lumber is the most common use for mixed plastics. HDPE (milk jugs) becomes nursery pots for the plants you buy. PETE (soda and water bottles) becomes insulation for your jacket. Beyond the first recycling, about the only thing that can be done with plastics is to use them as fuel (e.g. trash to steam plants).
I toss mine in the creek out back
It for now stores it in very large trashy warehouses. As it has over a 10 year supply of good plastic chips in storage. Vietnam is the last Country still taking plastic scrap. We just refused to take a shipment from Canada here this week of trash. What the U.S. does with there trash is up to them as long as they keep it there. Or maybe turn Venisualla into a big dump.
Plastic which is not recycled goes to a landfill
Whatever you put in recycle goes to the factories and what's not plastic gets discarded.
Recycled plastic is not disposed, any more than survivors of a plane crash are buried.