That is a by-product, and a testament, to the complexity of the software.
Take Word. It has millions of users around the world. And everyone of them uses at most a different 20% set of the full features 80% of the time.
But, it's only one software. It has to satisfy everyone.
So you end up with a reasonably complex UI that everyone has to bear.
However, you can customize it, and I wish there was more documentation and more effort put into customization of the menus.
I mean, let there be a menu customization system that is fully drag and drop, rather than the clunky stuff presently there. It would be a game changer.
With some reluctance, I agree with you. But it does bother me that I rarely use much of that complexity, while still being required to engage with a UI that seems mostly designed around hiding things that I don't need anyway. I wish there was a way to use the Office apps with a simplified feature set. Of course, I understand why not: everyone's essential features are different. So I carry on poking at ribbons looking for things.