We have a ACF setup with image fields and gallery fields. All images are restricted to the post.
But we need users to be able to delete images and files – that they have uploaded. Their user role is Subscriber. How can we change these capabilities / permissions?
There isn’t any way to give subscribers the ability to delete media files without giving them access to the media library admin.
There are plugins that will allow this like https://wordpress.org/plugins/capability-manager-enhanced/
But this will give them the ability to delete any file, which I think you do not want to do. You will also need to create an pre_get_posts filter that runs in the admin when loading media files that only shows files that are uploaded by the user if they are a subscriber. https://www.wpbeginner.com/plugins/how-to-restrict-media-library-access-to-users-own-uploads-in-wordpress/