Yeah, I remember switching from CVS to svn in.. the late 90s? I am not sure when? I think cvs was already a well established thing by 1992, with many people using it. (and others using proprietary version control systems). But it's true that it wasn't yet as universal as it is now, small shops might or might not use version control.
I got annoyed in the 80s with people who had messed the code base up so we could not compile from a fresh checkout.
Yes communication between people was and still is the most important thing. Note that this usually needs meetings in person