Part of the reason was Dyson took a long time to catch on here. It wasn't until at least the 2010's that Dysons became a household name. They were also so expensive that people didn't bother with it.
Finding an upright Dyson is somewhat difficult, you do not see them every day. I have NEVER seen any in 5 years of thrift store trips. Not even an accessory or tool, nothing. I got all mine off eBay when I can find them less than $50 with shipping.
Getting parts for older models is hard too, sometimes the only option is getting them from England.