Didn't they launch only their first device (considering this is the sixth generation) in the USA a few months ago? Hopefully the replacement parts are yet to come. I'm not sure why it's so difficult, perhaps it's that they're stretched too thin and barely managed to get the base device to market there at all
I bought one a few years ago. Good device, too big for my hands (back then, there were still smaller options so I bought one of those smaller ones in second-hand). Not having spare parts available would make me hesitate since that's like 50% of the point (fair sourcing being the other half), but besides that it's a (big) phone like any other