Once again, you are (wilfully?) missing the main point. The technology in North American phone switches is different from that in the rest of the world.
The inter-switch signalling in Australia was already set up to handle numbers of differing lengths, so it was not a big deal to change lengths of numbers incrementally, since those longer numbers didn't affect the switches that don't handle the numbers being changed. In North America, the 3+3+4 format is wired into the hardware (and now into the switch software.) Like it or not, longer numbers will require changes to every phone switch in the continent. That's the real issue, not the consumer answering machines, stationery, and other junk.
We'll have to make numbers longer at some point, perhaps 30 years from now, and the telcos are thinking about how to do it, but it'll be a huge project.
R's, John