I assumed that this was going to be a fashion thing.
Odd shoes have always been a thing for hipsters (or whatever previous decades’ hipsters were called) but recently there’s a trend of shoes that off the shelf deliberately don’t match. e.g. this kind of thing. [link goes to YouTube video]
I will admit to wearing mismatched socks. But only my heavy wool or polar fleece socks that I wear with boots when I walk the dogs. I wear the heels out of my socks for some reason so if I wear one of them out, I’ll save it and wear it with the next pair that one sock gets worn out. But they have to be the same kind of sock - the only difference would be color.