The End to End apps here are used for both local testing and development and in some cases for full UI Testing integrations in the Build Pipeline. These are not necessarily examples meant to demonstrate best practices. They are however meant to provide the team the ability to validate functionality.
More complete and stable samples showing how to use Prism for your application development will be posted in separate repositories under the PrismLibrary GitHub organization. These samples are based on public released NuGet packages and are thus more stable than the sandbox samples. Guidance on specific scenarios can be found in these stable samples.