That isn't true (and was never true). Trash in Asia that ends up in the ocean is local trash.
Even back when Asia bought recycling from us there wasn't much trash in it, and even the trash that was there didn't end up in the ocean.
The stuff in the ocean is what litters the streets, and then goes in rivers during rain storms.
But you are right, the amount of councils sending recycling to landfill is very sad.
https://abcnews.go.com/International/plastic-garbage-flip-fl...
https://www.bbc.com/future/article/20180426-why-plastics-are...
https://www.surfrider.org/coastal-blog/entry/microplastics-f...
https://www.cbc.ca/news/politics/ocean-plastic-liberals-fact...
And it's only going to get worse unless we do something about it. Recycling is far worse than just taxing negative externalities and making the companies upstream use biodegradeable materials.
Or at least, it used to. I think most plastic "recycling" is now going into local landfills.