To be fair, they did somehow manage to take over javascript while nobody was looking.
The versioning logic is fairly simple (although kind of pointless afaict?). X.1 —> X.9, and instead of going to .10 it simply increments major number. With average releases every 3 months, then major versions are simply being bumped roughly every 30 months.
I think functionally it’s just a really awkward date-versioning on a 30 month calendar instead of 12