Believe what you want.
I know for a fact that Harvard reads all applications.
Harvard even interviews all applicants-- or makes an attempt to. I can’t tell you how many interviews I’ve done where the kid had an 86 GPA, two Ds and an F on his transcript— and still I had to interview him.
It is frustrating to me to spend my time doing this when I highly suspect they have no chance of being admitted… yet even so, Harvard tries to interview all applicants
I can’t speak for Columbia or anywhere else…