Same here, unfortunately. Once, years ago, I was forgotten about for like an hour in the exam room (like the nurse did the blood pressure and such, then the doctor just...never came in. I finally checked at the front desk, and they admitted they'd forgotten about me). I get that emergencies happen, but I think they should find a way to communicate with patients that they're running late if it's 15 minutes or more.

At my current PCP's office, they'll sometimes announce if the doctor is running more than 30 minutes late, in case people want to reschedule and leave (like if they have to be back at work).

Though it's not just MDs...my former marriage counselor also would sometimes be 30 minutes late, which bothered me. My current therapist will text me if he's going to be even 5 minutes late, which I really appreciate.