For that matter, I still buy boots made in the USA and they're less than 2x over boots made in Vietnam.
Made in USA is just part of it and it doesnt strictly mean it was ecological process.
For example where was the cloth made? Coloring is where lot of the worst stuff happens.
I don't really like sensationalist documentaries because it's never accurate but try "True Cost" or "River Blue".
Dumping untreated wastewater back into the river will always be cheaper than treating it, but dye residues in particular are fairly easy to treat so that the waste water is again safe to drink. Dyeing enough denim for a pair of jeans with proper post-treatment for wastewater is only slightly more expensive than doing it by dumping the untreated wastewater. But if there are no laws or weak enforcement, a lot of companies (individuals for that matter) will behave destructively to save less than a dollar per unit.
Also while it might relatively be cheap to treat water like this in US.. in under developed countries it would be more expensive. So pick your poison i guess.
Same, if someone can point me to ultra-cheap leather shoes from the developing world that're anywhere near as good as the ones made in the US and Europe I'm absolutely mercenary enough to be all over that (aren't lower prices supposed to be the main way normal non-capitalists benefit from globalization, after all?). Savings seem to be at best ~40% vs. comparable products made by much more expensive OECD labor.
https://www.theguardian.com/sustainable-business/dyeing-text...
Unfortunately you also have no chance of knowing if your 1500usd hoodie was made well or by kid payed 12usd week.
Its hard to expect other outcome since many brands are regular startups with investors. There are few monopoly megacorps like LVMH and Kering that act much like Facebooks and Googles and just squeeze anything for their investors and demolish/buy competition.