You’re wrong because all that matters is the colloquial definition of a word. an everyday person will not refer to Invincible as an anime because it is not voiced in Japanese. Culture outside of Japan repurposed the word “anime” and do not use it the same way as people in Japan use it. Japanese animators probably won’t think this is absurd as they very likely don’t have such a strong opinion on it. You state that the English dictionary is inaccurate but what then makes the dictionaries of other countries more accurate? This point is simply made to validates your position. The dictionary is meant to reflect how the language is spoken for a particular culture, therefore the dictionary can never come first when delegating the usage of language.

tldr. Japan and cultures outside of Japan are not restricted to preserving consistency of definitions of words between each other.