Typically, IME, it isn’t up to the doctor how long you wait for an available room. The nurses and nursing support staff (nursing assistants if there are any) determine when you get put in which room. That’s probably true of most places unless you really think the doctors clean/prep the exam areas between patients…
Clinic back ups are a common problem but it isn’t always because of over-booking or money-grubbing or people not giving a shit about their patients or whatever else gets tossed out in these types of threads. It’s because of the mother who (through know fault of her own; she’s not a doctor) starts obsessing about Junior’s every sniffle and whine and thinks that every single little thing is a relevant sign or symptom so an appointment that was scheduled to take just 15 minutes turns into this big thing about poop and “What’s this thing here on his skin?” and now that doctor’s whole day is totally fucked even IF every other case is super easy, in and out (which, of course, they won’t be).
There’s isn’t a real solution except to really try hard to not be a part of the problem yourself but, unless doctors and nurses are going to REALLY start slacking on patient care, you’re always going to be behind the old man who is so hard of hearing (like, nearly deaf) that it’s difficult for him to understand the patient teaching, which then takes 35 minutes instead of the 10 minutes the nurse had before YOUR appointment was scheduled to start. Or they could start seriously under-booking, but then you’re waiting 8 months for an appointment. Not really feasible.
None of this is to say that you shouldn’t be made aware that everything is behind and you’ve likely got a wait ahead of you. And you could ask. Clinics around here actually encourage that by posting signs that say if you’ve been waiting more than 15 minutes you should see the receptionist. Just don’t be a dick to her; it’s DEFINITELY not her fault.