I'm not a fan of G10 because it fails to excel at anything in particular and is over-used (especially black G10). There is extremely little functional difference between G10 and FRN in terms of strength. G10, however, is usually heavier than FRN and has a gritty, scratchy texture that devours pockets and makes knives uncomfortable for extended use without gloves.
At the same time, G10 lacks the novelty and appeal of expensive handle materials that are equal in strength or stronger, including carbon fiber, titanium, and aluminum.
Ultimately, G10 is extremely popular because it is versatile, relatively cheap to produce, and for whatever reason, leaves consumers with the impression that it is a "quality" handle material.
I'll take carbon fiber, titanium, and natural materials over G10 any day of the week.