In my current job, for the OSS project I worked on -- it's got VCS history dating back to 1995. Yes, I have traced changes, design decisions, old relics, and even bugs back nearly ~20 years. Why? Because it was easy and there, and the best way to discover why something was done. It is absolutely one of the most important discovery and historic tools, for this reason. Many developers -- including myself, use it all the time.
I have to second this. When I was working on the VCL component of LibreOffice I often had to backtrack through positively ancient history to try to understand decisions.
Unfortunately, history before 2000 is not available, and even worse was the absolutely stupid decision someone made to merge changes but not keep commit history for branches - consequently there are poor summaries of multiple changes for a single code commit. It can be incredibly frustrating!
I'll third this. I hired a guy, a really bright guy, and put him to work. He was debugging some problem, I think a windows problem, and found the file that contained the code with the problem, looked at it, and said "this code is gross, I'm gonna rewrite it".
Did I mention he was bright? He was, and he took a look at the history in bk revtool (a graphical tool, shows you the dag, you can left/right click on a pair of nodes and see diffs, double click on a node and see that version of the file).
He double clicked on the very first rev and lo and behold, there was the code he was about to type in. He said it was exactly how he imagined it.
Hmm, says he. I wonder why it changed. He started clicking around and went "ohh, so on this OS they have that problem". Some more clicks "oh, and windows has this problem with wrapping pids". Etc.
Had he not had that history (and had it not be really fast to click around and see it), he would have rewritten the file to be back where we started, losing all the bug fixes.
History matters. Being able to see it quickly and easily matters.
I have to second this. When I was working on the VCL component of LibreOffice I often had to backtrack through positively ancient history to try to understand decisions. Unfortunately, history before 2000 is not available, and even worse was the absolutely stupid decision someone made to merge changes but not keep commit history for branches - consequently there are poor summaries of multiple changes for a single code commit. It can be incredibly frustrating!