Lots of "should"s, but we're talking about advice on using git, not "any decent source control system". This is a problem I see with people not understanding git. They treat it like they think it should be treated. Like it or not, that's not going to work for git.
You don't give python advice to a C++ developer, regardless of how much you'd like C++ to be like python.
This logic also works on computers. Or, well, anything. You'd be surprised at just how useful people can find things while still making a mess of them.
So, yes, if you have the time, learn the internals. But no, that is not in any way a prerequisite. Nor should it be.
> You'd be surprised at just how useful people can find things while still making a mess of them.
You mean like this? http://www.thisiscolossal.com/2017/12/tatsuo-horiuchi-excel-...
User level documentation should be sufficient for user actions. If someone wants to learn internals, great; but this should be an option, not a requirement.