Is that a fact, or you just parroted other people who made similar claim?
I still use the mouse from time to time when editing text mind you. But for most actions, I would not think of moving my hand to the mouse, because it is slow.
Even before vim, I made gratuitous use of end of line navigation via keyboard (home/end buttons; cmd+arrow keys). vim is just a more powerful version of those buttons.
I make no claim that vim is the MOST efficient platform ever created, but it's a lot faster than mouse+keyboard and/or out of the box editing methods.
https://ux.stackexchange.com/questions/30682/are-there-any-r...
I always found this “faster” claim somewhat stretched and zealous. I don’t need to type fast. I need the editing routine to gtfo of my mind when I’m programming.
> I don’t have to plan ahead how many times to press an arrow
Usually, I'll just do something, e.g., hit dd to delete a line and then even though I could hit "3." to delete three more lines, I'd usually just repeatedly tap . to repeat that dd action. It doesn't really matter if the action is deleting a line or commenting/uncommenting it or changing capitalization or modifying a word in a certain way. The general strategy of doing the action you want and then repeating with . it is very useful.
The modal nature of Vim is one of it's key features and makes a lot of sense. If you consider the keyboard the primary, if not singular, means of interaction, then there will be times you want to use the keyboard to type text and times you want to use the keyboard to control the editor behavior. In a "normal" editor, you have to use modifier keys to enter commands. In Vim, you do it by changing modes. It's actually quite powerful but you can't get past your own assumptions about efficiency.