Originally Posted by kovidgoyal
I know I, who wrote many of those capabilities, use only a small fraction of them
I fancy myself to be a power user. Yet, I too only use a small subset of Calibre features. But, and it is very important But, I use different subset of features than you or other users. This is what makes in such a great program. This is exactly reason I like for example Vim text editor. If you need some obscure, super-specialized feature it is there, waiting to be discovered.