That's like trying to give a catalog weight to humans by demographics.
There are infinitely too many factors.
Consider something simple. Every rider chooses their tyres. Tyres can vary by weight vastly. TPU vs latex? Tyre liner or not?
Same goes with saddles, seat posts, pedals, cable housing. Basically if it can be removed from the bike, it has its own weight.
Another thing I can think of is change in manufacturing. The "same" bike can indeed vary by weight, and wrong would still be wrong in this woke day and age. Manufacturers don't want to defend themselves just because someone caught them underweighing a bike by 50 grams.
A LBS would be more than happy to help a buyer using a scale in their store, this has never been an issue.