I keep seeing stat scaling being used. I just want to mention that nobody has shown that a specific class/spec scales better than other classes/specs, let alone fire mages.
https://www.warcraftlogs.com/zone/statistics/26/#dataset=95&aggregate=amount&sample=7&itemleveldisplay=scaled
https://www.warcraftlogs.com/zone/statistics/26/#dataset=95&aggregate=amount&sample=7&itemleveldisplay=scaled&difficulty=4
Also, poor sub rogues and survival hunters.