Here's a scenario: you're hacking on Ruby code in pry, and it's a mess.
Blocks chained on blocks, variables named a and other_one, assignments to
_. You can understand it, but nobody else can, and one extra } breaks
everything.
The solution is the edit command. Typing edit in pry loads the current
buffer into your editor of choice. Jump in there and turn those inline blocks
into do/end, assign some variables, write a method: iterate on some quality
code in the comfortable, predictable setting of your text editor.