My understanding is that the overwhelming majority of recycled material just ends up with the rest of the trash.
I'm asking because over the years I've hoarded an incredible amount of the plastic flower pots that house plants come in, and I've recently admitted to myself that I'm never going to use them. I'd chuck them all into the recycling, but they're all dirty so I have to wash each one individually, and I'm not sure if there's any actual point in doing that.
As others said, plastic recycling is a joke and most of the time you shouldn’t even bother. Paper it depends, it has to be clean (no pizza boxes) but clean dry paper is okay, may be worth it depending on your area.
Aluminum and glass are actually recyclable, you basically just melt them back down and they’re good as new again. Easier with aluminum than glass, the best method for glass is to return them, wash them, and reuse them, but for some reason the US got rid of its infrastructure to do that like 60 years ago. But melting glass down also works well, if not as nice as reusing.