Question Why is everyone enabling and disabling action maps?

Trying to understand the new input action system, struggling to get to the part where I can read the value of the input.

That aside, so many tutorials for some weird reason keep enabling and disabling action maps. Why? THey only have one action map made, just seems like a weird way to needlessly overcomplicate your code by turning things on and off.

Why? What have I missed? If you need to use a different action map, why not just switch to it?