Less that Japanese like to have luxury brands, more that the market here seems to demand it.

Cadillac is fancy Chevy. Audi is fancy VW, Genesis is fancy Hyundai, etc.

At least at one point I think Lexus wasn’t a thing in Japan, they just were Toyota models.

Pickup trucks seem to buck the trend, your fancy ass 100k truck needs to still be a “good ol F150”.