They’re still very a small U.K. centric company and that’s an American-heavy study. Monzo are so small in the US they might as well be non-existent, and in terms of tech and finance Chime do what they do and have a much larger following.
You really need a global brand with global recognition to get included on those things if you’re not a big American company. There are few exceptions but you need to be really stellar in a certain thing. Like John Lewis showing up there, because time and again in the U.K., they’re one of the few companies in the world known to live up to Apple’s level of customer service and satisfaction, to the point they’ve even beaten them from time to time in U.K. polls. This gets them recognition in the US too, because a company doing something Apple is well regarded for better than they do makes headlines over there too.
Monzo just don’t deliver that sort of standard in the U.K. either imo. Though it is clear they’re an influence, and the more Americans copy the more that may change. I do remember when Apple announced Apple Card, and much of the discussion was how it looked like a little U.K. spending app called Monzo.