> High end selvedge jeans might run a couple hundred bucks, but they will last a decade.

Is there any data supporting this? Because while I think this is our intuition, i.e. "it's expensive therefore it's better quality," I wonder if there's any way we could verify this other than anecdotal evidence.

You see the British aristocracy wearing 30+ year old shoes that look as good or better than they did when they were new.

I think it is common sense that emissions are far lower for extreme-luxury clothing that can be repaired and is timeless verses disposable clothing that last one or two years.

We're not talking extreme-luxury clothing here though. We're talking Ralph Lauren vs H&M, or something similar. What the British aristocracy wears is probably hand-made stuff by world-class artisans. What Ralph Lauren makes is mass produced in either Europe or China, so it's a much closer comparison to H&M (not to mention still within the reach of an average person in a rich country)

I'm not sure if jeans that are torn/blown out can be seamlessly mended the way shoes can be.

Low end selvedge denim lasts longer than a decade and even low quality denim lasts. You don't wear stuff out of fashion though, it would be like wearing the best of the 90s. You're also assuming that the clothes get worn. The cheaper stuff may just be worn as much as the high quality stuff or that they continue to be used.