Dry firing will certainly put much less wear and tear on your firearm than actual firing will...
That's true as an overall statement. However it's not true in the specific. That is, overall
, the gun will experience more wear from actual firing but in specific, certain parts
of the gun are stressed during dryfire in ways that they are not stressed during normal firing. The breechface and the firing pin are two of those parts, and, not coincidentally, those are the two parts (primarily the firing pin) which are sometimes broken during dryfire.