DFW Airport is the best pickup zone for Uber in the whole metroplex. Business travelers tip well, the rides are long, and surge pricing hits during peak arrival times.
But the queue. Oh my god the queue. I've waited 45 minutes to an hour in the staging lot for a ride. Sometimes longer on slow days.
The math works if you get 2-3 airport runs in a shift. It doesn't work if you sit in the lot for an hour, get a $12 ride to Irving, then drive back and wait again.
Best strategy I've found: start mornings at DFW airport (6-9am business travelers), then switch to Uptown/Downtown for the rest of the day.
The airport game is feast or famine. I've had $80 rides to Plano and I've had $8 rides to the rental car center.