It's like Hawking Radiation... but with socks.
"They never come back as a pair, so one must go to a different universe."
That's inherent to the phenomenon- the socks always appear out of nowhere as a pair, just outside the drier, but the other one gets sucked back in.
The bad news is that this means your drier will eventually disappear. It's unclear if the gradual loss of mass due to this quantum-related sock phenomenon is the reason your drier stops working after a few years, or whether that's due to it being a cheaply-made piece of disposable junk the manufacturers want you to keep replacing.