Improvements in mole removal

Just out of curiosity

About thirty years ago, my mother had a large, raised mole on her right breast removed. While the removal was certainly an improvement, it did leave a scar and a depression in the skin.

A year ago I had a very similar mole removed. While there is a slight discoloration where the mole had been, the area is perfectly flat and the discoloration is getting less and less.

I'm curious as to why my situation turned out even better than my mother's. Is it because:

[1] There was a difference in the moles (perhaps my mothers penetrated the skin deeper)? OR
[2] Methods have improved over the last thirty years? If so, how?

Thanks very much,

Betty