Especially when the Wright brothers plane could fly properly and under control, flying 24 miles, including many turns, a year before Dumont could barely manage a few hundred meters in a nearly straight line and ended his flight in an uncontrolled roll.
Dumont made a flight of 50 meters in 1906. Dumont's 1906 plane had no ability to do turns, rolls, or banking, useful maneuvers when you take a flight. It was not something that could be considered a usable airplane.
For decades most orbital rockets took off in an easterly direction, effectively using the earth's rotation as a catapult. Does that disqualify them as successful orbital flights?
Did you take the airplane out, start it up, and take off? Like a modern, independent airplane? Or did you shoot it out of device first, because it wasn't able?
And not even particularly important, by the way. The last time this kind of argument was novel to me was in the mid-nineties at Slashdot.
So yes, it is simple. The Wrights flew without "shooting it out of a device" years before Dumont. The Wright Flyer was also capable of lateral control, like a modern, independent airplane.