When I was a 19 year-old Marine I listened to a captain talk about communications and military operations. He told us stories about his part during the invasion of Grenada and his time in Beirut. In the 1980s, very few Marines had seen combat, so his thoughts carried a lot of weight.
The captain had some insightful experiences. One point he made was about, what he called, the communications pipe (we call it bandwidth, nowadays). As a communications pipe increases, more stuff gets added. The problem is that we always fill it to capacity. The upside is as bandwidth increases, the older technologies, like text chat, can shine during a crisis. His point resonated with me on 9/11 when I couldn't reach my boss and fellow Apple coworkers in NYC via phone or e-mail. But, AIM, being such a low bandwidth channel, worked without a hitch.