"Between planes, airports, and hotels, a WiFi connection is usually always available to her. "

But most people DONT spend their entire lives in major transport hubs.

Most people spend most of their lives away from wi-fi connections (and heck, even within my own flat I have trouble getting a wi-fi signal in the bedroom).

Without some kind of cellular option you will never ever have an always-on connectivity or anything close to it. You might not like the business models that cellular companies use, but you cannot deny that cellular networks have a far more comprehensive coverage of the world.

Because of cellular I can connect when I'm on a bus for example, which is impossible with wi-fi.

This idea that somehow removing cellular would bring us better connectivity is lunacy.