>>63889941
Like the other anon said, you can find well-preserved high quality swords in most cultures. The difference is that Europe kept on fighting its many, bloody wars and the pressure was to keep developing and doing the "new" thing. Swords simply became less and less relevant over time. Japan got the Edo period where you suddenly got a huge unemployed warrior class and you needed to do something about it. This is where a lot of the actual romanticized ideas of bushido and the sword as a sacred object come from especially since carrying the daisho was essentially your badge of office.