Emacs resembles a musical instrument, and a pretty complex one:
An instrument, that can be transformed and adjusted according to the player's wishes and needs.
Learning Emacs, we start with the basic movements, then learn more advanced ones, combine them, develop muscle memory; such that an idea born in a brain almost instantaneously gets realized by fingers.
Most musical instruments require several years of constant practice for a person to start playing smoothly. The same is with Emacs. I'd say it's even more difficult with Emacs, since there's no instructor behind a shoulder, directing and correcting each move, advising on the next one. Though, to some extent, probably built-in manuals fill in this gap. The rest we frantically search for in the vast valleys of the Internet.
Now, this explains why there's nothing wrong with being relatively slow in becoming productive with Emacs. This is a natural speed of mastering sophisticated instruments, especially so instruments of an art.
Emacs is an instrument for the art of text.