Personally it wouldn't surprise me if the upcoming Windows 10 integration with certain Xbox One/Xbox Live features is part of a long-term exit strategy from Xbox being a hardware-based console to more of an identity of a PC service.
However, I will say this - the notion that smartphones are cheaper than consoles is in many cases just an illusion, as the cost of the phone is built into a person's phone contract and paid over time. Some smartphones are quite a bit more expensive than a console. (And who knows, the games could potentially be more expensive if someone can't control themselves. But that can be true of any platform's games with DLC and microtransactions.)
They are more expensive, but as Sharky said, you don't buy a mobile JUST for games. It's a device that lets you talk to people, text, skype, watch videos, check emails, surf the web and play games and it fits in your pocket. It's much more valuable to most people than a console.
City Rush is deeper than the originals.
You unlock shit, customize shit, compete in leaderboards, complete challenges for limited time taxi parts, drive your friends taxis, git gud
In terms of gameplay? I couldn't care less about paint jobs and upgrades.
I doubt it has the same finesse required to dash, drift, limiter cut, and pick the best route through the city.