Hello,
The Accessories category is showing because it’s set as the default product category. Default categories cannot be deleted or hidden.
To remove it you need to change the default category first:
Navigate to Products > Categories > Find the “Default category” setting.
Select a different category from the dropdown menu, or create a new one to serve as the default.
Now go to Products > Categories and you should be able to delete the “Accessories” category without any issues.
Best Regards,