Some scholars like auction catalogues, some ignore them.
Older scholars do.
I am not an older scholar, I do not even have any formal scholarly credentials, but I love them. Very often you may come across copies of variations of well-known paintings. Here and there you will come across a signed example of a work by an obscure, little-known painter. Of course those scholars compiling catalogues raisonnes have to pore through old sales catalogue. That is a given.