Carhartt is said to have gone down in quality. And the problem is also they tend to sell at top dollar used too.

Maybe you can look at some military or fireman type generic coats. Or I’d suggest going to a Tractor Supply or Rural King store and seeing the off brand, generic Carhartt style coats there.

I also came across this brand Schmidt while thrifting that seemed very durable. Not sure it’s in business anymore.

Anyway if you want like a nylon jacket, cordura is a brand name fabric that luggage is made out of, as well as Jansport backpacks. I think it can probably be made into jackets.