Even the Petroleum Institute has admitted that previous generations of "recycling" was a scam, but swears that this time it's real, is my understanding of the situation. In fact, I seem to recall speculation that most of the plastic in the Great Pacific Garbage Patch was "recycled" plastic that had been shipped from the US and Europe to China, then dumped into rivers there and ended up in the Pacific Ocean, because plastic recycling wasn't just a scam, it was actively negative for the environment.
Just to be clear, recycling is good (paper mostly works out, aluminum for sure), but plastic recycling in particular is largely a scam designed to assuage people's guilt at how much plastic they use.
Bury everything currently on the surface of the planet and replace it with material from underground?
The earth doesn't filter the byproducts out. Burying isn't a solution. It also doesn't address the behemoth scale of plastics already in the environment which will continue to release byproducts into our water.
Maybe what we need is a strong will to solve the problem, no lobbying to prevent the funding of the necessary research or restrictions on creation of plastics, and so on. Similar to how the space race and nuclear programs more or less got all of the money, resources, and agency required to get the job done.
It seems like the reality with plastic is we've become insanely good at making it, but nowhere near as good at dealing with its externalities. We can get better at it.