The fact is, you don’t need new clothes in most cases. I mean, until fairly recent history most people only had a couple of outfits — one for daily wear and one for church. If one got a rip or hole, one repaired it. If something became too damaged to wear, only then would it be replaced. Likely with the same thing (the pair of jeans on wore in the field would be replaced by another pair of the exact same jean which would be the only ones they carried at the general store and were made to order).
Obviously, this would not work for most today. But I point this out only to say that fashion and the idea of having multiple items of various pieces of clothing is a fairly recent idea history wise and it can be a useful reminder in taming our own desire for more and directing our attention from want to need.
The interesting/good thing is that there are many modern manufacturers who either recognize their own environmental impact and wish to make sure their values are properly aligned with their business (i.e. Patagonia) or see the growing interest in re-use/re-sell as an opportunity to be exploited for profit (i.e. Levi’s, probably). Smaller indie brands are getting into this game too (See: Ministry of Supply). Even fast and fast-ish fashion brands like J.Crew are dipping their feet into the archive/re-sell game.
Regardless of motivation, there are an increasing number of ways one can get used gear directly from the producers one might otherwise buy new from. And if for some reason you do need a new pair of jeans or tech-bro fleece vest, it is at least worth a check to see if you can get something gently used versus new.