360BakTrak "Without one you wont have the other, so whats a tail and a dog got to do with anything? "
OK mate another metaphorical way of looking at it my be "who came first the chicken or the egg?"
In the case of aviation it was aircraft and then after a while we got ATS, no aircraft - no ATS, no ATS - no...... well actually there would still be aircraft but ops in many ways would be severely reduced, so it is without a doubt an essential service but not a prerequisite for flight. Imagine the Wright brothers being told "Nice contraption lads but this is transponder mandatory airspace so none of yer hopping about"
So in essence ATS units are there to serve pilots, if you dont like the expression serve try assist, big difference.
Finally as The Rev Bob Marley said No women - No Cry