> So my question here is that in a hypothetical scenario where terrorists are using whatsapp to coordinate an evil plot, which to most people would fit a scenario where Facebook can and should help the government - what is it that Facebook can do to help a government?

This logic has been used to justify mass-surveillance and degrade encryption for national security and "protecting the children" narrative. The problem is that governments also use this as a way to suppress civil liberties.

What if the government declares a journalist uncovering a multi-billion arms deal scam or some human-rights violations as a terrorist ? In the eyes of the law this qualifies the government to acquire private messages. Why should the government have this power ? The hardcore terrorists and journalists know about encryption and will setup their public keys for encrypted communication. It's the common man who is affected by such stupid legislation.