What’s the point ?

• Back in the day, electronic sound making devices were very simple – usually you could get one note at a time out of a ‘synthesiser’, and you might need a separate box if you wanted to apply an effect of some sort. To get richer, layered sounds rather than just a single tone meant using more than one physical device. So at its most basic, that’s what MIDI is for – being able to build up a complicated sound using multiple physical devices.
• Today an electronic sound making device can make much more complex and sophisticated noises, and they are very very much cheaper. But that means a musician can easily have at their disposal an array of such devices, and they still need to be told what to do ( the devices, not the musicians... ).
• So the basic problem hasn’t changed – musicians want to be able to control multiple devices, in real time, to get the sounds they want. This is why MIDI has survived pretty much unchanged from 1983 – which is generally a sign that it was a great design.