None of this requires a separate mode to do. Modifier keys have been shown to be enough to give commands for doing operations other than inserting characters.
The modes are what makes editing in Vim efficient.. you don't think Vim users are out here swapping through modes looking for the one that lets them paste a line do you?
For me, the other big advantages are staying on the home row as much as possible and reducing chord shortcuts. I used to use Emacs but pain in my left wrist led me to search for a way of editing code without Mod+Key on one hand. I have some custom keymaps in vim that allow me to move to the start/end of a line with Shift+H and Shift+L, move up/down code blocks with Shift+K and Shift+J, and page up/down with Ctrl+K and Ctrl+J. In most standard editors, I find moving my right hand to the arrow keys and home/end to be unreasonably slow and error-prone in comparison.
That said, I'm not an evangelist. I don't care what editor other people use and I'm not sentimental about vim. It's a dinosaur with a lot of legacy cruft and I would switch to something else if I could reproduce a similar setup.
Vim isn't the only editor with shortcuts. Many of the IDEs listed come with pretty of shortcuts and you can configure more if you want. Those editors also let you use shortcuts without having to switch through different modes making you more efficient.