I just saw a show on the BBC tonight which laid out how the US government propagated the myth that 'flying saucers' were from outer space in order
to deflect attention from their research programs. These programs included the F-117A which accounted for many of the triangular UFO sightings of the
time.
Unfortunately, that explanation falls down when you review UFO sightings and pictures (after photography was invented) covering events from before WW2
into the 1800's (and back).
So, yes, I would believe that the Military-Industrial machine would rather you think their latest radical plane is a UFO rather than what it really
is, for it is to their benefit to keep that information from other nations.
But, no, just because the Military-Industrial machine may have a flying machine that can do basically everything a "UFO" can do, does not mean a
"real" UFO does not exist.
Basically if one-million UFO sighting are bogus, but one is not, then UFOs are real.