your dad could have built all the boing planes in the world! that doesn’t mean anything here.
the question isn’t whether the plane can take off or not standing still.
the basic question is whether THRUST (by a propellor or by a jet) will move a wheeled object when the ground under those wheels is moving in the opposite direction
and the answer is yes. it will move. the wheels will just spin faster in the forward direction. if the backwards moving belt matches the forward speed of the object, the object’s own thrust will still propel it forward but the wheels will simlpy be turning twice as fast.
the fact that it’s a plane has nothing to do with it.
best way to visualize this is to put a toy car on a conveyor belt
then, as the source of thrust, use your finger to push the car from behind
as you accelerate the toy car forward, the conveyor starts accelerating at the same speed but in the opposite direction. the car is still being pushed forward by your finger, except its wheels are now spinning twice as fast. the car still moves forward.
the conveyor moving backwards has no effect on the forward motion created by the thrust from your finger pushing
got it?