Welcome to earth. Here outside the US there are countries that recycle up to 35% of plastic waste and intend to recycle more through regulations on types of plastic used and improvements in processes. https://www.scb.se/en/finding-statistics/statistics-by-subject-area/environment/waste/waste-packaging/pong/tables-and-graphs/recycling-targets/

It’s not dwindling, it’s not dismal and it’s certainly not pointless.

To bring it back: choosing to not recycle your plastic because you think only 5% of it will get recycled is indeed as stupid as throwing away your pizza crusts and thinking it doesn’t contribute to food wastage.