Why is the “average life span" given as a range?
This guy has been in his job for over 30 years. He uses a flip-phone, and has encouraged me to do my own repairs on multiple appliances over the years. He is not trigger-happy on replacement.
I expressed surprise that the machine needed to be replaced. It was barely 7 years old! I have already replaced the pump, and two washer assemblies. I asked him what the average life span is for a typical dishwasher these days.
His answer: 7 years.
10yr for hard users, 20yr for light users. Most people are presumably in between.
Edit: On second thought the lower bound is heavy use, the upper bound is probably "we can't guarantee all the rubber won't degrade and leak after this age".
As for our Miele washing machine - it is still going after almost 30 years! The main bearing is going so it is VERY LOUD and unfortunately not economic to fix. The Meile tech I asked said the failure mode would be leaking water so I said we'd wait for that. Still doing OK 2 years later :-)