I assume that they want very specific salary information, i.e. what Bob makes on Integrations vs what Susan also makes on Integrations vs just what people seem to make at SDE II.
I think the more important question is whether comparing Bob to Susan (or Sam, or whomever) is helpful. I would argue it's not, that it's even unhelpful, unless you know a whole hell of a lot about how Bob and Susan got to where they are right now. Did they have competing offers when they were hired? Did they negotiate a [non-]discretionary bonus into their package? Did they negotiate more PTO or profit-sharing in the form of a non-discretionary 401k contribution? These are all things that won't be immediately obvious but will affect their individual numbers. In aggregate, these aberrations get smoothed out. I don't see any benefit in comparing individuals to each other, but there's a lot of benefit in comparing individual to the average.
A cynical take, for sure, but I can't think of any other reason why anyone would do this over something like you mentioned.