I don’t buy the “more failure-prone” thing if “failure” is defined correctly. Here’s my comparison:

1. Assorted old appliances I have experience with. I have washer and dryer buttons (possibly the last LG model that had them, purchased quite deliberately) working flawlessly after quite a few years, and I have experience with some high-end old dishwashers that had absolutely perfect button performance for about 20 years.

I can compare this to new high end dishwashers where turning the thing on requires triggering a capacitive power button that is very very hard to trigger deliberately even with completely dry fingers. I’ve seen two different related models of this unit with the same problem - they are effectively “failed” almost immediately. Never mind that these dishwashers react to anyone leaning gently against them.

So my score is: near 0% failure rate for mechanical buttons and near 100% for capacitive sensors.

(Even the really nice capacitive sensors on nice phones and watches don’t work well under kitchen conditions, so I’m not sure this problem is fully solvable even with more expensive capacitive buttons.)