I've wrote an entire critical analysis on this question in the past, in summary these labels exist to easily define ones sexuality, though these terms are generally not used in conversation with those who are not that invested in the queer community.
For example, I have a friend who is a purplegender transfeminine fin-oriented aroace, but generally just explains their identity by saying they're a trans girl attracted to femininity.
I believe animesexual and fictiosexualities are exclusive to aro/ace/aroace people whose lack of attraction differs when dealing with fictional or anime characters, and outside of those conditions, yeah, it could be called merely a fetish.