There was an article (maybe came across HN) not that long ago that details the history of MS-DOS and Windows, and they made note of how originally MS-DOS was go

There was an article (maybe came across HN) not that long ago that details the history of MS-DOS and Windows, and they made note of how originally MS-DOS was going to use \ as a file separator, and instead of C:\ it would've just been C\, but due to some deal with IBM (I think) they wound up switching their path conventions. Because all the old code supported the more conventional pathing it was essentially just left in, and over time it's meant that Windows generally handles \ and / pretty well at the OS level.