[shmerl]

What's the alternative? If you will try installing random stuff you'll get dependencies hell. Another extreme is self contained software, when each application bundles its own dependencies. Android does that more or less. But such approach causes major bloat and also increases security risks because you need to patch each application and its dependencies (which are duplicated in the multiple variants) once vulnerabilities are discovered.

Any better ideas than these two?

[jimmaswell]

The bloat from self-contained software really isn't that much. It doesn't cause a space problem even on the small amount of space on an Android device.

[shmerl]

It depends on how many dependencies we are talking about. And more than bloat, security issues are critical.