It’s not just about airfoils. It’s about dynamic removal of the boundary layet through suction.
Give me $10 million and I can create aircraft with the observed speeds with 1946 technology.
And to give you a sense of just how remarkable even some historic reports are, run an internet search and read the Cowgill letter to Scientific American in the late 19th century.
Cowgill, an American consul in Venezuela, describes a UFO incident in Maracaibo in which lights hovered at night over an Indian village. Several Indians closest to the lights received radiation burns from what seems to be induced radiation on the side of their bodies nearest the ground they were sleeping on.
At the time, the phenomena of induced secondary radiation was unknown and no humans had the ability to generate such an episode of a hovering radiation source. Indeed, even with $10 million in hand you could not duplicate the incident today.