"Didn't really matter how large my team was when the VCS was VSS."
It does matter - because how you manage code means what integration issues you hit or avoid - and how developers learn to work well in a team or not.
Hope you also had external backups of your zips, if your disk crashed....
Also I wonder if people working with VSS had all the needed updates installed, or, if working with "unknown sources" copies, never installed a patch.... or never run analyze to check for database issues, because RTFM is hard.... or run it out of FAT partitions instead of NTFS with all the risks of a crash crippling a repository.
VSS was bad, but with some efforts it worked, in a time when there wasn't many choice, and many developers had no clue what was a given version of a file.