Basically, if your Uber driver starts using a traditional GPS instead of Google Maps, get worried. That's my experience using Uber in LA for longish trips out to Marina del Rey, anyway.
(Going the other way: "The LA convention center? Where's that?" "Right next to the Staples Center." "Do you know what streets?". I did, but really? I'm from New York and don't have a driver's license, and _I_ know how to get there...)
It seems like a flaw in the Uber app that the customer can't just provide an intersection or an address, and the driver gets immediate turn-by-turn navigation. Yes, Uber still needs to blind the driver to destination until pickup, but it's not a huge obstacle.
The other thing is that users just HATE typing in addresses on smartphones. It's like the worst-case scenario for smartphone data entry -- lots of different fields, and words that are not in the dictionary/don't autocorrect well. So Uber (and Lyft, and (ahem) Flywheel (which I work for)) do not require that a user input a destination.
The deal is, some passengers are convinced they know the best route from point A to point B, and will accuse drivers of trying to con them if they don't take that route. So if the passenger has a route they want to take, even if the route is stupid, you just shut up and do that. Otherwise, you take the best route.
In theory, of course. I have no doubt that there exist cab drivers and Uber drivers who run up the meter. Hopefully, Uber does some monitoring of routes and catches at least egregious cases.