Different people should use different words.

I don't think a content creator would naturally describe themselves as a content creator. The word is useful for contexts where you need to generalize over all the different types, but that's not useful when speaking about yourself. So a writer says "I'm a writer", not "I'm a content creator." But writing this paragraph, I needed a word to generalize.

P.S. The closest alternative word might be artist, but it's not quite right--some writers are artists and some aren't.