Almost all writers start out bad. Trust the process
I see a lot of new fanfic writers say they wish they were as talented as this or that other fanfic writer who writes so well.
The truth is that even for natural born writers, almost no one starts great. There are lucky people who's first piece is amazing but that's 1% of the writing population.
A lot of amazing writers didn't get that way overnight. They wrote other stuff before they started posting on platforms and they write under different pseudonyms that they don't publicly claim. You don't know their beginnings (the embarrassing pieces they wrote before the stuff they've posted).
Fact of the matter is that you learn and improve by practice and by being committed to doing what it takes to get better. Personally I believe that fanfics are for fun and enjoyment, so you can write them any way you want;
But if you really want to write excellent stories, don't obsess about comparing yourself to other writers. Obsess about writing and learning to do better( by reading in general, consistent writing, using tips on how to write better, and doing research on whatever topics you want to add to your story).
Be patient with and kind to yourself. You'll get good too. It's that way for everyone. There are no shortcuts
