Today permissions apply on an origin level, no more granular than that.

If there's any part of what an app might do that is out of bounds of what the user wants, then the permission request is illegitimate and the user says no.

Or, more likely, says yes but feels bad about it.

A force that leads to people being less willing to try new things.

Even a small bit of illegal territory gives you a no (or a begrudging yes).

But this means that huge swathes of legal territory are not permitted because there are small bits of illegal territory.

Information Flow Control allows applying it more fine-grained, so there is more that can be permitted without including any illegal territory.

A huge amount more possibility can be unlocked.