It’s always a question if the source is still around now or on accessible media. Especially if said products were part of one or more acquisitions. Source control usage has only been popular the last 20-25 years. Before Linus wrote git, the Linux kernel was kind of responsible for even making the idea that source control systems should be part of the development process in popular OSS. Zip files, tarballs, directory dumps were popular in the early and mid 90s. Super hard to get sources out if it’s stuck on a special machine that wasn’t network connected, maybe exotic media like WORM drives, kangaroo drives, backpack drives, 5.25” floppies, etc.