Imagine a GPS (or SatNav, if you're British) in 1971. There was such an idea, but since the satellite technology wasn't there yet, it came on pre-recorded cassette tapes that gave you directions as you played it. Watch how it works in this clip from the erstwhile TV show Tomorrow's World. Of course it could never work as advertised. If you ever made a wrong turn, the whole system would suddenly turn useless. Or if you were caught in a traffic jam, didn't drive the speed the cassette expected, or the machine ate the tape- which was a fairly common occurrence with cassettes. You would need to buy a new cassette for every new route, and once you drove there, you wouldn't need that tape again. I'm sure there were more reasons not to buy into this system. It would have been easier (and cheaper) to learn to read signs and maps, develop a sense of direction, and ask someone as a last resort. -via Nag on the Lake
The magic of smartphones is that they got huge economies of scale for equipment that can do all these things, driving the price down from thousands of dollars, to trivially inexpensive. The business models of subsidizing the equipment with the monthly service plan, and manufacturers selling at a loss to try and break into the lucrative market also greatly help drive prices down to the point you can pick one up for $30 today.
Her: Uh, western.
Me: Have you passed Atlanta yet?
Her: Uh, I think so.
Me: No, you don't drive through Atlanta and not know it.
Next call
Me: Where are you?
Her: Nashville.
Me: Nashville! You've taken a wrong turn.
Her: No, it's Asheville!
Me: So you took the eastern route.
Her: Yeah, I guess.
Next call
Me: Where are you?
Her: Lexington.
Me: Lexington? You've gone too far! Turn around!
Her: Wait, the sign says Lexington. With an arrow. I'm still in Tennessee.
Me: I give up.