FondotsNo shoes are truly BIFL if you wear them regularly, but these come close
grrgyleI can’t remember if I heard it here but I have heard (and feel, anecdotally) that cycling between wearing two different pairs of shoes leads them to lasting longer than if you wore one pair until they fell apart then a second pair until they fell apart.
I don’t know how that could possibly work unless giving shoes a “break” rather than wearing every day extends their life somehow.
My evidence: I have had a separate pair of running shoes and walking shoes for a few years now.
In addition to the leather stuff the other commenter mentioned, foam gets compressed during usage (especially running shoes with a lot of foam). It can take several days for the foam to recover. If you run in the same shoes every day, you aren’t getting the full benefit of the foam, and you are basically beating it while it’s already down.