I've reproduced some of my old map documents in ArcGIS Pro, believing there would be some efficiencies in this. When I export these layouts to PDF, the resulting files are about 5x larger than the same maps exported out of ArcMap (~5MB vs < 1MB). The export options are set-up the same in both Pro and ArcMap and I've also experimented with Resolution (dpi) & Image Quality, to no avail. Even at a 96 dpi and "Fastest" imagey quality, I'm getting 5MB PDF's.
Any thoughts? I've looked all around and cannot find any articles addresses this issue.