Because, let's be real, it's a mystery that has plagued the ages.
It's like they vanished into thin air, leaving only a few lone singles in the drawer. We've tried using the laundry fairy, the sock goblins, even hiring a team of highly trained hamster engineers to search for them, but to no avail. The Sock Police have been notified, and they're on the case.
chartInstance: Solve the Sock Riddle
Other theories: