I don't dry fire, maybe because it seems like a dull exercise, but I'll not criticize someone that has found dry firing to be beneficial. How does one measure the advantage of a much dry fired gun over one that has not been dry fired? I assume some here may be speaking of a benefit other than a smooth trigger or maybe reduced trigger pull weight, but I really don't know.
I seldom modify any gun, other than maybe adding a scope to a rifle. If a gun doesn't shoot well straight out of the box, I generally don't keep it long. I've had very good luck with Colts and Smith & Wessons (mostly revolvers), but I enjoy J-frames because they are quite challenging. I shoot often, almost exclusively with my own cast bullet loads, and usually single-action Bullseye style at 25 yards, but I'm certainly not an excellent shooter. Many of my S&Ws were purchased new more than thirty years ago. I think they're all pretty smooth from honest use, but I don't recall any of them having unacceptable triggers when I bought them. I'm not gadget-oriented so don't use things like laser sights.
Just a different perspective on the subject, certainly not something worthy of argument...