[devit]

A lot of people would probably deny camera permissions to Instagram (and upload by sharing from gallery if they upload content), and their reputation would take a significant hit (currently they aren't known to covertly gather any personal data beyond generic OS-provided statistics).

Also Instagram isn't really essential to communicate and learn about events in the way the main Facebook service is, so stopping to use it is highly feasible.

[robbintt]

Agreed. I just checked my setting and apparently did this "deny and post from camera roll" by default. I have no doubt I was just making a privacy conscious choice.

[kennywinker]

You can’t post instagram stories without giving both camera and microphone access. This is a significant leverage point for a lot of people.