The antenna point is very well made.
However, on roaming, I don't think that's true. In Europe, at least, we now have caps on roaming costs - which will fall further.
Many travellers, I suspect, buy a local SIM or get a specific roaming SIM.
That's what I did when I went to the USA - bought a T-Mobile PAYG SIM for a few dollars. Of course, I was locked to 2G because my phone didn't have the ability to connect to the US 3G frequencies.

I guess I'll just have to buy a Satellite Phone 🙂