Back in 2000, our builds, C modules to be consumed by Tcl, Apache and IIS modules, DB drivers took about one hour per OS for a full platform release.
OS being Windows NT/2000, Aix, HP-UX, Solaris, Red-Hat Linux.
Yeah, that's similar to my experience. C++ projects commonly took a week to build in the 90s.
I can assure that wasn't the case in our desktop software for Windows, and that already feels like trolling.
Not even Nokia NetAct took half as much, given its complexity of distributed CORBA services written in C++, nor the CERN TDAQ/HLT builds I was responsible for.
You were probably working on more competently designed software than I was, but sure, desktop software for Windows usually didn't take that long.