Lol, there are many different types of curry. That’s like saying noodles. It encompasses Italian, Thai, Japanese, Korean…
Yes, food doesn’t have boundaries and fusion food can be great. Your point about people graduating from Indian to Thai still doesn’t make sense in that context.
You can also take the opposite and look at fortune cookies. Invented by immigrants and now associated with Chinese food. Is that any different to a foreign person creating a recipe in China with Chinese ingredients, or a French person in the UK using Chinese cooking techniques.
Is tempura less Japanese because the batter originated with Portuguese traders?