It’s going to take generations for it to be fixed, and it probably won’t happen until humans and other animals get much much sicker.
We can just go back to the material we used to use for shoes: leather. If there isn't enough cow skin for shoes for 8 billion people, we can just vastly increase the amount of cow farming we do. Oh wait...
My last pair of quality leather shoes held up nicely for about three years and it's now relegated to construction and garden work. My current pair is spotless after two years. The soles on these are synthetic, but they degrade about as quickly as the tops. Not sure where you draw your experience from, they don't match with mine.
EDITED TO ADD: Of course quality shoes can be refurbished with new soles, so even if a leather sole would only last a couple of years, you could simply get a new sole slapped on.
>Most plastic-based shoes are worn out much quicker than quality leather shoes would be.
True, but there's tradeoffs here. For hiking boots, for instance, some people swear by "sturdy" hand-made leather boots, but the problem with these is they're much heavier than modern boots made with synthetic materials. For a lot of hiking, you don't want heavy weights on your feet, and the shorter-life tradeoff is worth the performance improvement. I'm sure the same goes for most other sports. Just look at the shoes that professional athletes wear: they're probably plastic-based, and it's not because of cost, it's because it's better to have something that's as lightweight as possible and performs as well as possible, even if that means throwing them away after one competition.
I've hiked quite a bit in various types of boots and yes, It's nice to have lighter shoes, but for most people most of the time a kg more or less won't make the damndest bit of difference. Only a fraction of all hikers are attempting trails under circumstances that require top-notch performance gear.
Anyway, I do agree about using synthetic material for the soles, and leather construction doesn't necessarily have to be super-heavy.