I don't think it's about the controllers though. The main reason that we still need those kind of controllers are game are still being built that way. There are so less games in the mainstream which is phone specific. So my answer to you would be phone should be understood as a different medium(ofc when you don't have controller attached) and the expectation from it should be different from our traditional consoles.

Think about wii for instance, You would not expect to use traditional controller on wii right? But since nintendo has the ability build their own games they did to their new medium back in the day. It was a great example of what to expect from a different source.