To be honest when a user visits the webapp without an internet connection, being greeted by a basic screen that says ‘Could not load network resources’ is pretty basic and doesn’t really explain the problem in simple terms. Perhaps there could be some customization available for people who would like to change what that screen says, align it more with their branding, etc.
Maybe in the far future there could be an option to download certain sections of the webapp to the user’s device so when they go offline and reload the page they can still use the webapp to some degree.
Please upvote if you like this concept!!