You may be interested in this recent reddit thread about Japanese French cuisine.
https://www.reddit.com/r/anime/comments/537bio/spoilers_shok...
Asian pears : Japan softball sized, US hardball sized
Carrots : US carrots are hard to cut Japanese style (really is just julienned) because they are so narrow at the fat end. Roll around on the cutting board like a marble. US carrot about the thickness of my thumb. Japan carrots were fat like a silver dollar and were easier to slice into stackable sheets.
Apples : I liked the cheaper apples (Fuji) in Japan. Weirdly the more expensive ones were less tasty and larger. The Fuji's probably size-wise same as the US.
Grapes (the expensive hot house types) : Japan's were sized like a small plum.
Strawberries : seemed more uniformly large. Still damn tasty.
Anyway, those are my kitchen observations.
Anyway, my reasoning for the taste difference is pretty simple and obvious really. US fruits and vegetables are predominantly of GMO and it's not the same type of fruits and veggies as several decades ago. It's a sad state really.
Visit New England or the Pacific Northwest in the September-to-late-October apple season before claiming Japan is superior in apples. Hell no they ain't.
IMO Indian spices are much harder to get right, whereas French cuisine relies much more on very expensive ingredients.
I disagree about the size & appearance. I wouldn't say this means the veggie would be more tasty. But I definitely agree on the taste part.
This is something I found in common between French and Japanese cuisine: Simplicity, but very good quality ingredients. (maybe this is why there's so many 3 Michelin stars in Japan)
In the US I would say it's hard to enjoy good French/Japanese for that reason. On the contrary, it's easier to enjoy the cuisines which relies more on spices, such as Indian cuisine, because those spices taste good everywhere.