It's entirely possible to trust something to work one way (e.g. keep a trivially restorable backup of previous state) when you do one thing with it and not trust it to do the same thing when you do another thing with it (especially if it's something you do infrequently or have never done before). The advantage of cp compared to git is that it only does one thing (more or less), so you don't have the potential for "doing things you're unsure of" in the same way as git.