Better Choices for rebuilt Alternators????

Why do most of us just "trade in" their Alternators for a rebuilt. Is it impossible to get a replacement Brush set for Mopar Alternators?? The VR is external. So no VR to fail. If the Bearings are good then we are just paying a bunch of $$ for basically a cheap set of Brushes. For 5 years I put Brushes in Honda alternators as long as the VR was good. I can't remember even one ever coming back.