I think kimchi just doesnt have that kind of broad appeal but who knows. This is not to deny the effectiveness of Korea food diplomacy. Im just noting sushi as a really extreme case.
Often their SKUs, IME, are overpriced and low quality, because they market it as a health food and try too hard to cater to that niche, so it’s not spicy or salty enough and lacks fish sauce. You’re still way better off going to an Asian grocery store for it.
But eventually they’ll figure out they can just sell the good stuff… It’s a great snack and Americans are already familiar enough with eg dill pickles and sauerkraut that I think we’ll eventually embrace real Kimchi.
Sushi has the benefit of needing to be consumed fresh, except for fake crab which freezes well enough that you can find "sushi" at quite a few out of the way gas stations as well.
Having access to an asian grocery store with fresh bean sprouts, kimchi, freshly made kimbap, good masala blends, all the herbs and so forth is probably the only thing I miss about living in a bigger city.
That said, rural folk in this part of the country are more likely to appreciate a fresh kimchi than they would soft stuff; the same goes for sauerkraut (bagged vs canned).
It would probably be better to compare kimchi with wasabi or sauerkraut though.
I come from a mid sized city in a less developed part of the US and sushi is much more available there now than 10 years ago. And yes 10 years ago most people 35+ in that area found it strange