Why so many redundant click in Win11

What do you mean by "right click menu, top bar on explorer, outlook, etc"?

Do you mean, "Why can I right-click, click a button, select form a menu, or use a keyboard shortcut?"

If that is what you mean, then it's existed a LOT longer than just Windows 11 - multiple paths to the same outcome have existed in UI for many decades: the [semi] common initialism is TMTOWTDI (There's More Than One Way To Do It)

And you offer multiple paths so you can be accessed by as many people as possible

Is it redundant to have a Copy button, be able to press Ctrl-C, go to Edit -> Copy, and right-click -> Copy?

Of course!

But it's also free to do.

Why not offer multiple ways to accomplish the same thing?