- Apps declaring how much space they need
- The OS enforcing that size as the quota.
That's it. There's no need for the OS to figure out how much space to give to apps.
This way, if I install an app that is purportedly a 2GB app, I'll know exactly how much space I'll lose.
If an app needs more space after an update, that update would require a manual approval from the user.
Something tells me that if app developers were required to be honest about their disk usage, and knew that he users would have to agree to a "This app wants 5GB more space after an update, are you OK with that?" prompt, we would not be where we are today.
On top of everything else, I wish Android versions were held to the same standard, and that phones were advertised with the amount of free space available to the user.