The UK has a massively milder climate than most of the USA, which provides significant assistance to things lasting. As I noted in another comment below, roofi

The UK has a massively milder climate than most of the USA, which provides significant assistance to things lasting. As I noted in another comment below, roofing slate is essentially unavailable in the USA due to geology - what does exist is of much lower quality than a good welsh slate. Still, in some ways I agree with you: roofing materials in general in the USA are far less durable those used in the UK and Europe, for reasons that I don't entirely undestand. That said, it amazes me that huge numbers of people in the UK live in essentially uninsulated and almost uninsulatable buildings. Sure, winters are mild, but anytime you have the heat on in the millions of homes built post-WWII, a huge amount of is just leaking through the brick walls. US stud framed construction has its problems if done carelessly, but it does have the benefit that its easy and obvious to insulate your walls to some degree, and not hard to do it to Passivhaus standards.