The fun fact is that you dont even need to sim yourself to actually understand how good frost mages scale with gear (stats).
There is an actual “in game sim” called Torghast. I’ve done a deliberate “test” there picking only damage abilities that increases stats and stats only, i’ve ignored things like aura damage increase or cast time reduce on frostbolts etc. I ended up with over 2k intellect 30% crit chance 25%haste (1.6 sec frostbolt cast) 35% mastery and arround 13% versatility. My dps went from “zero” to hero.
Now in upcoming patches were these kind of stats will be obtainable even by casual players you can imagine how well frost spec will be performing. And in next oatches new conduits and legendary powers will also be brought making us even more powerful.