I agree with that. I don't agree with that:
It's more like: "Very few classes have solo builds which can reach over 20k sustained DPS".
Back to topic: Scrapper is known as a very nice open world spec:
good damage (but solo DPS around 9k?), barrier and background healing for sustain, lack in condition remove unfortunately, decent mobility due to superspeed, nice options to break defiance bar.
Mechanist gives huge damage boost (I reach 12k, you reach 14k), good sustain (Mech as a a tank, incredible background heal), better condition remove and better mobility (Switch Signet). and even better options for breaking defiance bar.
Won't call it "broken AF", but hell: it is definitly S tier for open world. Or am I wrong?