How did the CLI (command-line interface) come about and what was this need?

It always had, but it was so natural that no one talked about it much.

One of the reasons is the increase in the complexity of managing these tools. And people tend to be more productive using simple data entry. A GUI, or WUI, may be useful for improving resource discovery, but it is no longer productive. That's why I always say it's common for current UIs to be wrong and unproductive. Is it possible to be productive with GUI if you know a lot what is doing, on the Web é is much more difficult.

But the big advantage is being able to automate the execution of certain tasks when you have this, although I think a more direct API would be a better solution. Even in DevOps culture becomes mandatory.

Then came out of necessity, like everything in you. It's just a matter of understanding whether it will be the best solution to the problem, or a new variable in the equation that can make the problem more complex.

In the general sense neither gives to do as it arose because it has decades, many.

I can't imagine what Windows has to do with it. Linux and other operating systems have the same, or at least similar, functionality. If you are saying that Windows has no command line, it has before even being Windows, it has always had.

It is clear that all this can be done via GUI or otherwise, but it does not allow the same flexibility or practicality.

Particularly, although I think it's good, I think the simplifying some things would bring such an effective result that a CLI would not even be so necessary.