Yeah it's definitely eye of the beholder. A congruent example I can think of is a lot of immersive 3D games going more minimal on the UI, using plain text overl

Yeah it's definitely eye of the beholder. A congruent example I can think of is a lot of immersive 3D games going more minimal on the UI, using plain text overlay and no visible style, e.g. Ghost of Tsushima, where I think the UI style helped the goal of "immersive". I can see Pokemon S/S is going for a more realistic or immersive 3D world and can benefit from a more minimal UI, but to me visually it turns out to resemble too much to the typical "flat design", and my personal visual taste is stopping me from understanding what it achieved on the game design level. And I agree there're places like "hub" where it's more disconnected to the game world, and you can say it's less important for those to use a very consistent style. I would argue these places should also be fun and game-like (or, the UI interaction feedback should match with some of the in-game feedbacks), but that's more experimental and a different subject.