I don’t remember the names of the studies because this goes back to when I was studying business, though we touched on similar studies of human behavior in criminology and the same mindset appears when studying mass delusions in crowds and other large groups.
It has to do with group dynamics, not about “disingenuous” or “fake.” Many people tend toward pleasing others in group settings for a variety of reasons. Some is age-old brown-nosing, but it could also be fear of speaking against the group, lack of power (or perceived power), boredom or just wanting the session to end for another reason (having to go pick up kids, e.g.), imposter syndrome, previous experience with not being listened to, etc.

You put a bunch of people in a room and you frequently end up with a less-than-ideal consensus because it’s the only thing everyone could agree on. See also: Congress.