I didn't read the previous reply closely. My fault.

Some cameras do have issues. For example, the Rolleiflex 35mm SLRs, particularly the SL 35 M/ME and E often have faulty electronics. The SL 2000 also is known to be unreliable.

I've seen some electronic issues with the Minolta XD and XG cameras.

I think that you can say that the simpler a camera is, the less likely it will have problems. That is a generalization, and there are plenty of exceptions.

I've had lots of mechanical issues with Petri SLRs. Maybe I just have had a bad run with them, or maybe this explains why they are no longer in business.

I've had maybe five or six Minox 35 models, and only one has a properly functioning shutter.

Yashica/Kyocera Contax models have been good for me, as have been the Yashica cameras that share the same mount.

Most Pentax K1000 models still seem to be working today, but for me the ME/ME Super has been an exercise in frustration when it comes to finding a working model. The Pentax MX has been a nice camera for me in terms of reliability.