I hear what you're saying.
But disagree with your profit margin comment and the time it takes them to be made. Plastic snap together frames from Oakleys, smiths, von zippers, ashburrys of the world maybe 15-50 mins a pair and the pull those things out of plastic injection machines.
to prep the wood, To cut these out, sand them, drill 'em, set the hinges, laser engrave them, cut the lenses, pop the lenses in, 20 mins. doubtful. Even if you are mass producing 'em.
My guess is closer to an hour a pair, plus each is unique and original no 2 pairs are alike.
As far as the sustainability, I'm not sure. Bamboo is super sustainable, the others I don't know. Wood in general is sustainable because it is renewable. So if it is regenerated or replanted its sustainable.
Durability, not sure, but they feel super solid, and i've broken plenty pairs of metal and plastic glasses so that goes with the territory I guess. but they feel super solid and well bit. More worried about a beaver attack than them breaking.
Anyway I feel like I'm pushing these things too much, I don't get into products very often and these things are killer I don't usually write reviews on stuff even. Super clean. well executed. After watching all the videos, I just fell in love with the story, brand and what they are doing. Feel they are legit and are actually doing something as a brand instead of talking garbage or being a soulless big conglomerate owned by some other company not even in the industry.
Bottom line just go get a pair and you'll be writing your own thread on 'em.