Playing a mage is a solid choice. You’re pretty much decent at everything and will have no problems getting into a raid or instance as DPS.
But AoE leveling … question mark. People don’t know this except mages who did it back in the day pre nerf, but Blizzard ninja nerfed pretty much everything at one point. Around 51, mages used to be able farm Mara for gross amounts of xp. But that was made impossible. Lashers in DM were also a thing, but Blizzard nerfed that too.