There's more to think about than just firing pins.
There's dryfiring and then there's dryfiring, and it's worthwhile to understand the difference.
Dryfiring won't hurt most guns, they're designed to shrug off the occasional snap, and most will even tolerate reasonable amounts of dryfire practice.
Dryfiring hundreds or thousands of times is hard on nearly any gun--after all, everything wears out eventually.
Just to be clear, I dryfire a LOT. But I do what I can to try to ameliorate the likely effects of constant dryfiring. And I understand that dryfiring is wear on the gun and will likely eventually have some sort of negative effect. I tend to do most of my dryfire practice with hammer-fired guns and use a snap-cap as well as some method of cushioning the hammer fall.