I’m sorry, but none of the provided arguments are actual answers for why not to allow the creators to share the files:
This can coexist with files still being available for download for more advanced users.
Creators who feel this way can just choose to not share the files on the marketplace. They are not forced to create technical support Discord servers either. Most will still sell them on other platforms as files.
Most of the avatars are gonna still be sold on external platforms with files. If a creator is concerned about security they can just choose to not share the files.
I cannot see how any of these answers are actual reasons to not allow optional sharing of the files.