This is pretty cool. Just needs clients for iOS and Android and it would be a rock solid replacement for a lot of large enterprises, or privacy minded companies.
Privacy, data ownership and reduced reliance on public clouds were definitely motivations.
A Java/Kotlin client is certainly on the short-list. We recently added one for Swift. There are also clients for Dart, TypeScript, and C# in case you're more into cross-platform app development (Flutter, React Native, and Maui/Avalonia respectively)