Here's how to think of Vim that will make sense.
Suppose you have two identical codebases that each need to have the same 200 lines changed. Functions need to be added, comments to be removed, templates need modifying, and so forth. In one of the two codebases, you use Nano to apply those changes. In the second codebase, you use Vim. Assuming the Vim user was proficient at Vim, you can be sure that he/she used 1/3 -> 1/2 as much hand and wrist effort than the nano user to make the same changes. It could be that the effective Vim user ended up using less than 1/2 the hand effort than the nano user.
If you extrapolate this over these two coder's careers, you realize that the Vim user is going to be glad he spent the time learning Vim.
Learning how to use Vim has been so rewarding for me. I love coding in Vim and I love learning new ways of doing things.