The article clearly states that data is stored on the device. That's the exact use case described - where people do not want any of their data stored on a serve

The article clearly states that data is stored on the device. That's the exact use case described - where people do not want any of their data stored on a server they don't control. If that's you, and if privacy is important enough to you to want a local-only app, I think you'll find a solution to back up your data. I don't think it's unreasonable to continue producing apps that do not require an internet connection to function and be useful.