Because you were in face to face discussions with people who knew you, you knew them and you all therefore had an idea of what each other’s personality was, truthfulness and importantly through social connection had a vested interest in maintaining your credibility.
I too remember such conversations, most people spoke honestly but there were also a small few who would exaggerate, make claims and statements that could not possibly be true. Others in the conversation could see this because they had firsthand knowledge of the person, and of course responded accordingly, often very bluntly.
You are making a false equivalence, this is not a face to face conversation between people who know each other.