So a long time might turn out to be a very, very long time indeed.
Of course, this will take a lot of storage space and logistics, and at the moment it's not cost-effective because plastic is so cheap to produce, but at the same time, I (again as an amateur) see it as a long-term investment.
We're decades late with what you're suggesting. The "long-term investment" did not happen. There is no conceivable way to collect it all up now, and it's in the fossil record for the long term.
1) https://www.theguardian.com/environment/2020/apr/30/micropla...
2) https://www.nhm.ac.uk/discover/news/2021/april/over-four-bil...
3) https://www.theguardian.com/environment/2020/nov/20/micropla...
4) https://www.nationalgeographic.com/science/article/remote-ar...
(1) https://www.newscientist.com/article/2187838-when-humans-are...
LOL, You mean like Astrophage?