Nowadays it is even harder to separate the wheat from the chaff than it used to be because the military has tons of high tech stuff that is secret—so a lot of what may be observed is military stuff.
Vallee’s position is that a lot of the 1950 UFOs were the real deal, but .gov got into the disinfo (and high tech) business after that, and the waters got very muddy.
He also argues that the “alien contact” stuff is mostly hoax, scammers, and disinformation (including intelligence agency “mind control” and “mass opinion modification” experiments). The real stuff is the modern mind re-interpreting what used to be called angels, fairies, leprechauns, etc. to fit the modern mind.
It is highly unlikely (as in unbelievable imho) that aliens would conduct genetic experimentation of humans—if they are truly advanced they should be able to manipulate DNA without resorting to “interventions” in human society—and they would be able to move about undetected by our senses and instruments.
Modern “science” is as dogmatic and close-minded as Medieval religion imho—neither will give us the tools needed to figure out what a truly advanced civilization would be doing.
Terence McKenna said it best imho—nowhere is it written that we hairless apes have a right to find out the truth about our world.
It is a human conceit that we are masters of the universe—we are not—again imho.