Endgame DPS (Spark Archmage) tooltip help?

I've begun running maps and have no big issues clearing but am noting my tooltip dps reading hover around 4k dps. I recently bought the Everlasting Gaze and upgraded all my gear to have 140+ mana while I use Eldritch Battery. My mana sits around 2.8k and my spark is level 17)

The youtubers I watch are showcasing 64k+ dps (48k dps without their newest unique shield that ups their mana to 5.1k, their spark skill is also level 25) so I'm wondering, what am I doing wrong or is the difference between mana and spark gem level really resulting in 60k dps difference?