Telemetry Replaces RC?

If the 3DR telemetry with ground station (APM) can let us use joystick on PC, then we can control our UAVs in the air without an actual Radio Controller, e.g. modern 2.4Ghz radio devices.

We do not need any other transmitter, only a pair of 433/915 telemetry transmitter can do it all.

What’s more, it also carries flight data in MavLink protocol which is so cool.

Did someone do this before?

what’s the benefits and disadvantages?