E-mail will never die. Nothing on the Internet, content or service, ever dies.
The advantage of keyboard centered communication is that people type slower than they talk.This helps to keep the communication on point. (This also applies to text chat.) In person or in video chat, it’s too easy to digress into talking about the weather, office politics, last night’s game, etc.
Do I need to see my colleagues ugly mug (or they mine) to make the communication more effective?
E-mail is also the way to go for conversations that span the globe. I’m on the east coast US and used to work with folks in Australia and Hong Kong. Fire off a question even as late as the evening my time, get the answer the next morning. No need for anyone to work from home or jigger their schedule.
Also e-mail, for better or worse, leaves a trail. My butt has been saved more than once by being able to use an old e-mail to resolve an issue.