Raymond Chen has got a video exactly regarding this! (https://channel9.msdn.com/Blogs/One-Dev-Minute/One-Dev-Quest...)

normal, modern dev with automated builds and git creates a build every time you commit (or every push), and you can commit for a missing comma so ... with 10 or more people working on it on a daily basis it can go up very fast

ah, yeah that makes sense - I was thinking of “releases” not so much “builds” and thats why it looked weird to me...

Also I believe that this is the kernel build counter, and it's the same counter that's used since Win95. Someone has published a list: https://www.gaijin.at/en/lstwinver.php

edit: it's not the kernel build counter and MS has cheated with it in the past, but it has stayed sequential across the whole NT tree (as this is where any post-2K Windows originates). https://www.howtogeek.com/140411/learn-the-secrets-of-the-wi...