Most of what I have seen came from technical debt aquired over decades. With some of the build engineers hired to "manage" that themselves not being treated as programmers and just adding on top of the mess with "fixes" that are never reviewed or even checked in. Had a fun time once after we reinstalled the build server and found out that the last build engineer created a local folder to store various dependencies instead of of using vcpkg to fetch everything as we had mandated for several years by then.