I have found that even slight brake rub makes a large difference to how much effort you have to put in, and the chances are that the rub gets worse as you ride, because you heat the rotor/pads, fluid & it all gets even more draggy.
Friend of mine borrowed my old Julies for a newly built bike while his new brakes were being delivered & when we stopped for lunch, the back wheel would only turn half a revolution before stopping. The disc was really hot. Once we’d had lunch, the wheel was much more easy to rotate, but within 10 mins, was back to half a revolution.
Are you using aftermarket pads? I was advised by my LBS to scrape the paint off the edge of the pads that most aftermarket pads seem to have, as my brakes were dragging. I did this, re-seated the calipers just for thoroughness & they now run with no drag at all. The paint around the edge was thick enough to stop the pad retracting when the lever was released.