The big one is that cell phone providers aren't that interested in telephony these days.
I did an extended stint of B2B sales over the phone and I can say that cell phones have made life much worse for anybody who talks over the phone. You discover that people in "normal" built-up places like Encino, CA are making calls on their cells with constant dropouts. Or that you can't get a GSM signal two blocks from the intersection of Hollywood and Vine, or you might even be unlucky enough to be on a conference call that is interrupted by a car crash. (It happened to me!)
Any criticism of the cell phone culture will get you voted down, after all, almost every article in a lifestyle publication leads with some reference to how attached we are our to "our" smartphones but the fact is that people are flapping their lips constantly but not all that concerned about understanding what the other people say, otherwise they'd ditch their cells for a real phone.
B2B sales over the phone can vary across the board from tedious to nerve-wracking to a lot of fun, but if you can't hear what people are saying, and they can't hear now, it is much harder. If B2B sales matter at all to the economy I'd imagine that cell phones are knocking a few percent off our GDP.
