title_body: Should VTX ever be lower freq./higher power than the control transmitter?
upvoted_answer: There's a few factors that you're missing. The first is that the RC world is dominated by traditional line-of-sight control, and 2.4GHz provides more than enough range to fly a model plane to the limits of vision. There aren't many long range system because few people need them. Even for FPV, long distance flying means a long walk or losing your model when you crash.
  The other is that control is very low band-width compared to video. A typical 2.4GHz protocol includes error detection and can reject a lot of packets and you won't notice so long as one or two get through every second - maybe even less when you're at extreme range and not manoeuvring hard. A video signal needs most of the data to get through to be flyable. Analog video has no error handling or rejection, and while digital systems do, there isn't enough spare bandwidth to ignore any data. Even a corrupt picture is better than black screen!
  Good RC systems these days do include RSSI (Received Signal Strength Indication) in their telemetry, so you know when you're reaching the limits of your range - and models with GPS can be set to return-to-home automatically if they loose the RC connection.
  Finally, it's entirely possible to use 72MHz on a quad, with a FC that takes individual inputs for each channel - however the range is no greater than on 2.4GHz, and there was rarely any interference rejection on the old analog radios, we used to use the glitches as an indication that we were flying too far away!