It's in the cache location because it's a copy of a plugin that was installed from a GitHub repository, so that's not the original point of truth for that file.
I agree with this, it’s frustrating that in 2025 apps are still polluting my home dir.
XDG may not be perfect but wiping related data for apps following it is straightforward. There are a few directories to delete instead of 1, but still consistently structured at least.