With the shoes it is due to the polyurethane used. The cheap ones use a urethane that is easy and fast to mould, but which has a massive drawback of a shelf life limitation of 30 months or so before it starts to disintegrate from oxidation, and which gives the shoes a 24 month shelf and operation life.
You can use a much more expensive formulation, which has much longer cure time, somewhat stiffer and a lot denser, so the shoes will last around a decade before failing. Incidentally even expensive brand name shoes use the cheaper urethane, price is no indication of quality.
As i use safety workwear I tend to buy a new pair every 6 to 9 months, as they exhibit this failure, but recently bough on clearance ( $50 after reduction, originally was a seller at $150, with a 5 year warranty) the last pair , which was also my size 12, so will be wearing those next year to see how they compare to the $20 cheapies from the shoe importers next door, which brings in container loads from PRC every 2 months, so I can actually ask for my size and style, and get then in the next container, 2 pairs off, for the $20 each price.
There is a shoemaker inland who makes leather work shoes, but as his are $ 200 a pair, i will have to just look and dream, along with those US made custom jobs, with a 3D printed titanium custom cap, custom shoe plate in laser cut spring steel, and stitched leather uppers and resolable leather and vulcanised rubber tread.
Got to find one of the local itinerant shoe makers though, looking for some Michelin thongs, the ones I love are starting to look a little tatty.