Alexis Madrigal ruminates on why no one answers their phone anymore:
When you called someone, if the person was there, they would pick up, they would say hello. If someone called you, if you were there, you would pick up, you would say hello. That was just how phones worked. The expectation of pickup was what made phones a synchronous medium.
I think it really comes down to this: synchronous communication is fraught with peril—not knowing what to expect, not having time to react, not trusting who will be on the other side—so we’ve all shifted to methods that are asynchronous.