cgw
Been spending a lot of time on here!
Zeiss Ikon only made durable cameras. If anything, they were over engineered. I have yet to come across a faulty Zeiss Ikon camera amongst the dozen or so I have in my collection. My oldest Zeiss folder is from 1926 and is in excellent condition.
As far as image quality goes, medium format film produces a very high mage quality - it is different to anything digital can produce and certainly not inferior.
Let's just say you've been lucky. Leaky bellows and gummy shutters are simply age-related maladies many examples of these fine cameras suffer from--problems that have little to do with build quality. In 2018 they'd be easier to love if competent service was more widely available. No interest in kicking the film/digital binary.