> In my opinion, Vim's normal, insert and command modes (the main ones) are very beneficial.
You mean, compared to not having the modes, as is true for all modern editors? In a normal editor, to put it in the simplest terms, I enter content with the letter keys, I delete content with the backspace key, and I navigate with the arrow keys -- no extra keystrokes required. If we count keystrokes, to put this plainly, a modern editor is much more efficient, and requires much less time to learn. If we count the time required to learn how to use an editor from a state of perfect ignorance, a modern editor is clearly more efficient.
When I designed Apple Writer in the late 1970s, I knew about vi and I knew what I didn't like about it. Even then, it was accommodating a nonexistent roll of paper, and its superfluous keystrokes were my primary target. I designed an editor that didn't follow vi's model, didn't have modes, and every editor since then has done likewise (except Vim).
If someone told me in 1977 that, 35 years later and counting, people would still be using vi's descendant with its modes unchanged, and explaining how beneficial it is, I would have laughed out loud.