Press End to move the cursor to the end. Then hold CTRL-SHIFT and hit left arrow 3 times to highlight the last three words. Press Delete or Backspace. It's just as fast as typing "$ 3b D" and is far more intuitive.
I know. It was just an example to illustrate the sort of syntax that you'll find more of.
If I myself actually properly knew Vim, I would have given you an example that by itself is most definitely quicker than normal keybindings, too. But I figured, if you actually care to understand, you'll see that it's just an example, if you don't, then you won't.
All I know, is that you can find videos of people using Vim well and they're most definitely faster than anyone I've ever seen with a normal text editor.
The big thing with Vim's modal editing is that it allows you to have keyboard shortcuts involving keys that aren't way off in the boonies. Some examples:
* / or ? to search for text
* dd to delete the current line
* Stuff like ciw or ci" will delete a word or the contents of a double-quoted string, and drop you into insert mode. I use this one constantly.
When prompted, people try to come up with really crazy complex things, but frankly the bigger thing is just being able to actually reach things.
If I tried to use shortcuts in other editors to the extent that I do in vim, my hands would constantly be in pain. This is why I never got into emacs, though I've seen some folks be terrifyingly fast with it as well.