For many people like me, the phone system is broken. And it is not all about costs or devices: as Andreas Klinger once said, telephone numbers are a disgrace to our generation.
His main point, one I agree with, is the disconnect between phone numbers and the identity of the people behind them. He says:
I have friends that have three numbers in their signature. US, UK, local-european-country-no-one-knows. This whole system assumes I want to call their cellphones. Which is not true – I want to call them. The people behind that numbers, simcards and devices…
Andreas stresses the need for a means to reach people regardless of where they are, what phone operator they are using or other details that are insignificant from the point of view of the caller.
In the era of email and, now, social networks, phone numbers are a legacy of the old days. Especially since the introduction of personal mobile phones, they often constitute an unnecessary level of abstraction between us and the person we are trying to reach.
As Andreas points out, what modern phones would need is an identity system to abstract phone numbers out of the way, just like DNS does with IP addresses.
While this is a significant problem that needs solving, it would require some infrastructure to be in place, as you can see by looking at the scenarios explored in the post.
However, there is a smaller problem that can actually be addressed with resources that already are in place. And I am sure we all experienced it at least once.