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@‭laserkittens‭ and @dmckee has already provided good answers, and I will not copy what's there.

Personally, I treat cli arguments as the default choice because of the flexibility it gives to scripting. Only choose user input when it's obvious that it's necessary.

A good case where you would like to have a combination is a program where unexpected things may happen during execution that requires user input. Like this:

    $ rm file.txt
    Are you sure you want to delete file.txt? (y/n)

In this case it's good to have this, but in that case also give the option to pass a parameter that adds a default option. So do it. In other cases this can be quite tricky

    $ myprog file.txt
    file.txt could not be accessed. Please specify another one: 

This would be very tricky to convert to parameters.