There are "home-brew" type radios that are designed specifically to send the "beeps" for morse-code. They don't have the capability to modulate voice signals, or any other digital signals for that matter.What communications systems would be limited to only morse code creating the necessity of knowing it?
People use it to "chat" on HF frequencies. Some say it has a slight advantage (in HF frequencies) over long distances because it is easier to hear through static. In other words, you could have a conversation from Arizona to Tazmania, bouncing your radio signal off the Pacific Ocean and the Ionosphere, and still get a clear enough signal through using morse code, when doing the same by voice wouldn't be possible.What is morse code used for these days?