Originally Posted by
2muchroad
I think with variable mainline rim brakes like Shimano 105, Ultegra, Tiagra etc. clearance shouldn't be a major issue if reasonably sized tires are used.
Modern aero disc brake rims are most often optimized for 28mm and wider tires with external widths in the 31+mm range. I have doubts that many rim brake frames and brakes have clearance for that, so the options for rim brake wheels with decent aero shapes will be accordingly few and far between. Being able to make wider and more aero rims is one of the biggest gains that disc brakes enabled.