Perhaps we cold buy other nations plastics and use it to make roads but that still does not eliminate the source of the problem. And as a side thing what would people take to the beaches to drink from. the plastic was shifted to to avoid glass. I dont know what is done with recycled plastics that are collected. I suppose they are being dumped in the oceans and that has to stop. Just like haz mat dumping in teh oceans by manufacturers is wrong the problem of eliminating it is a daunting one.
You can buy all the plastic you want, but that is like throwing deck chairs off the Titanic, Ghost Gear is the largest source of waste in the oceans. I've seen different numbers but the consumer plastic in the ocean ranges from less than 1% to as much as 5%. So even if you bought all the plastic from countries in South East Asia you aren't going to make a real dent until you tackle ghost gear.