Let me start by indicating that I consider my walking shoes as the main extension of myself and I use them to the verge of the extreme. I love my shoes. These are in my case Meindls, that from day one that I wore them, fit like a pair of gloves.
And yet I mistreat my shoes too. Besides the fact that I use them extremely often and in extreme situations, such as in the sucking river clay from the floodplain of the Dutch river delta to the North Sea beach where saltwater taunts their surface or in the ocher quarries of southern France and the mountain ranges of Tibet and Central Asia, I expect them also to outlive the test of time without any maintenance.
The effects of some of these extreme hiking activities are shown below: