Because the "Unix philosophy" is small, specific applications to do small, specific jobs. The Windows philosophy is bloatware spoiled by too many cooks.

All of them programs work!

A program is just a blind worker you can make work for you. Of course you need workers for everything you do. So there will be a program for every idea you can have.

No you don't. What you want is to build your program that does what you want in this fancy calculator.

The best workflow is achieved by a assorted ecosystem of tools.

If all you have is a hammer, everything looks like a nail.

Modularity is an important aspect of freedom of choice.

Buy a hammer.

So you only use one single software in your daily work?