Vim user here. I use the ESC key; I can hit it in a fluent motion while lifting the hand completely off the home row (much like a pianist).

It gives an opportunity to relax the hand. For the same reason I'm not a fan of hjkl and often use the arrow keys.

This. I never "learned" how to type, and while I've tried, I simple can't get rid of almost 20 years of muscle memory typing like a buffoon. It's much easier for me to use ESC and the arrow keys than people who keep their hands on the home row.