We have plenty here in the US. I live in a town of population 70K and we have at least a dozen charity shops and probably as many consignment stores. Any place in the US I've spent significant time I've found at least one nearby charity shop for the rare occasions I needed a suit or peice of furniture.
I don't know who told you we haven't adopted that system. Tell them to look for a Salvation Army, they're like the Star Buck's of charity shops around here, there's one on every corner.
Thanks for the correction. My opinion came from my own experience living in the US nearly a decade ago. In my entire 20 years there I saw a single Goodwill and no Salvation Army shops (though I'm sure they existed). Perhaps I was unlucky, or unobservant, or things have changed, but at any rate from that environment the UK was a revelation.
I don't know who told you we haven't adopted that system. Tell them to look for a Salvation Army, they're like the Star Buck's of charity shops around here, there's one on every corner.