The way a 2.4 system works is when you bind a reciever to a tranmitter, it stores the transmitters id code in memory in the reciever. The reciever will only listen to signals from that transmitter so the concept of channels is a thing of the past. Some systems like Futaba setup a pattern and freqency hop, some of them pick to clean channels when they power up.

They also reduce interference from things like noisy ignitions and metal to metal rubbing in the airframe because they operate well above the frequency of that stuff.

If you're buying new nowadays it's the way to go.