Even Mexican food at a restaurant 10 hours drive away from the border ain't real Mexican food. How far do you think Japan is from the continental U.S.? 8-)

Some said Vancouver has the best ones

Somewhat disagree with the totality of your premise, but In part, a relative scarcity of Japanese people compare to other Asian diaspora. Lots of non-Japanese asian enteprenuers will happily turn their menu into Japanese fusion or just straight up Japanese cuisine for the money. They may not always have the experience or familiarity to do it well.

Many Japanese restaurants in the U.S. are neither owned by Japanese individuals nor employ Japanese chefs. They’re often run by Chinese, Korean, or Thai proprietors. As a Japanese-American, I’ve even encountered a Korean and a Thai chef who falsely claimed to be Japanese. It’s always amusing when that happens!🤣 Btw if you ever come to the Atlanta area, go to Ginya or Shoya.

Try Rock Fuji Sushi in Glen Rock. Unfortunately, the price of seafood, the mass depletion of fishing stocks in the coastal US, and the quality of what we import makes sashimi lack a lot of what makes it special.