Leather shoe soles have worse grip than plastic ones. Switching will increase the number of deaths and serious injuries from people slipping and falling on hard surfaces. Leather soles also wear out much faster.
Are you kidding me? Even if that were true there are probably 500 ways of making leather soles equally grippy to plastic soles that would either eliminate or drastically reduce the use of these materials. There are also other biodegradable alternatives to plastic that could be used. Most plastic-based shoes are worn out much quicker than quality leather shoes would be. These are cheap excuses that are quite transparent in the attempt to justify simply changing nothing.
If there some reasonable way to make leather soles grippy, it would have been done ages ago I think. Instead, back in the old days, leather shoes that needed grip were probably made with rubber soles.
>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.
The "good old way" of making leather soles grippy is nails, just to give one example. Even using synthetic materials instead of hobnails would reduce plastic consumption quite a bit for these use cases.
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.
I guess you're a slow or easy hiker or something, because most people can immediately tell the difference between boots with a 1kg per-boot difference between them. I'm not even some kind of super-serious hiker, but I'm not going to choose boots that weigh double. Even walking around town that much weight would be annoying and tiring.
Anyway, I do agree about using synthetic material for the soles, and leather construction doesn't necessarily have to be super-heavy.
99% of people are „slow and easy“ hikers so I’m in good company (though I have hiked a couple of alpine long distance trails). We buy synthetic shoes because they are cheap, look flashy and are marketed on Instagram. I’m not saying that people don’t notice the difference, I’m saying it wouldn’t make a difference to their general quality of life if the affordable (or only) option would be a shoe made out of 95%-100% biodigradable materials. I don’t really care about the 0.1% of people who go to outer space or climb Mount Everest or the 1% who do competitive trail running. Let them wear all the “high performance” great they want/need. But the default option (due to price and convenience) for the rest of us should be something that does not pollute the environment for the next 1,000 years.
I'm talking about synthetic elastomer soles specifically, not the tops and sides of shoes. They last for decades and have excellent grip. There's no way to make leather soles anywhere close to as good.
That may be the case, but the last few pairs of "normal" shoes I bought had to be discarded after a year or so, not sure if the sole was still ok, but it didn't matter: they were done and because of their construction you couldn't fix them.
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.
