In retrospect it seems pretty wild that users were expected to actuate an explicit “save” command and that word processors didn’t just handle this automatically.
I’m sure there were real reasons - I was never involved in DOS or Windows programming but I presume it had to do with the slowness of saving to disk (and that a background auto-save wasn’t technically possible?). Or did we just not yet collectively have enough experience to know that auto saving was something critical to writers…?