Vim removes mental load while typing. It won’t make you significantly faster, or even really a better programmer in any measurable way. What it does is make the experience of writing text, and especially writing code, far more pleasant.

If I ever have to write something nowadays without vim, everything feels clumsy and imprecise. If I want to go back a couple of words and change something, I feel like I’m playing a timing minigame. I have to hold the left arrow key exactly the right amount of time. Most of the time I overshoot a couple of characters, and have to tap the right arrow key to get to the right spot. Now repeat the same timing minigame holding backspace. Ah crap I deleted too much better undo a couple of times. Now I can finally make my change.

All of this is just unnecessary friction between your brain and the computer that anyone who hasn’t learned vim accepts as a fact of life, but it becomes completely intolerable after spending the time to learn.

If you deal with many machines, it's very possible that they don't all have your preferred editor (unless it's vi). vi is on every POSIX system.