I've just declared sock mending bankruptcy.
(I'm talking about thin cotton ones, not thicker wood ones I've knit)
* darning them is basically useless: as soon as they have been darned they break somewhere else
* patching them with bits of other socks works, but takes some effort and I have a years-long backlog. really. it's a huge bag and I'm not going to go through it ever, and there are others in various piles around the house
* I need materials to fill a few draught excluders, and I don't have enough textile waste of other types (that I don't want to reuse in some other way)