I'm going to sub-skeet this because I don't have the strength or inclination to get into it with...strangers.
Copying is part of the creative process. Many creatives start by emulating their influences. You grow out of it.
Fanfic can be a part of that, or its own thing, or both.
Lighten up.
I have never understood how ppl have the bandwidth to get this worked up about what someone else does in their free time by themselves for their own entertainment that is hurting nobody