How to protect .assets files

As it seems, Unity deploys assets to resources.assets and sharedassetsN.assets (where N is natural number) files, at least on mobile platforms. As another post suggests, it is not so hard to extract e.g. textures from these files. I would like to discuss how such content could be protected.

Is the only viable approach to protection to use AssetBundles as suggested in “Protecting Content”? But what if I want to deliver the app without requiring the user to download anything after the app was installed?

I suggest encrypting the files you can do that through the unity editor, search up some tutorials on youtube for how to learn how to do so.