How did you get people you didn't hire to share with you their actual salary preferences, and companies that didn't hire you their actual salary ranges? Sounds like that would be super useful info
This is outside the US, but I just ask at the first call: please give me a range on your expectations to see if it overlaps with ours and that it makes sense to move forward and avoid wasting time. Everyone answers, most giving a number directly and few counterasking for our range for the position, which of course I disclose at that point.