Yeah, as someone who started with Costco rice and slowly moved up the quality chain, there is a clear difference in taste between even average Japanese rice and most Costco rice. It would be interesting to see a price/quality comparison between the U.S. and Japanese Costcos though.
This is one of these case where cross-country comparison might bring little relevant information.
Another example could be wine sold at US Cosco vs French Costco. It would be an indicator of something, but I'd personally be lost if I had to interpret it in regards to wine trends in France in general.
Snobs will tell you yes, but Kokuho Rose is a California grown sushi rice that's good enough to be served over imported Japanese rice at Japanese restaurants. Really disappointing that the farm
is closing up shop.
Speculating from online comments around it and from looking at bags of Calrose rice, they seem to be few decades behind in cultivation techniques and selective breeding improvements. The grains look smaller, less shiny and more yellowy. but technically they should be of the same strain.
Calrose, the primary rice grown in California is a Japonica, its just Japanese rice grown in America. Tamanishiki, which is one of the high grade sushi rices is grown in the US and Japan
Surprising, because while its widely available in California it seems to be a tiny minority of available rice. A search I did says it is 80% of California's crop, so presumably a lot of it is exported?
It doesn't serve every culinary purpose and most California grocery shoppers are not Japanese. You wouldn't make Moros y Cristianos with it. You wouldn't make Hoppin' John with it. It's no good for your Indian menu. It isn't really what you'd serve beside fried chicken.
There is no "best rice" any more than there is "best pants".
Jasmine rice can NOT be used for sushi! It's not sticky enough to hold together. The fact that it's not sticky makes it good for fried rice, not for sushi.
In my experience it's just barely sticky enough for sushi provided you don't wash it but I don't think the texture is right for that usage. I prefer it for most things though.