The fact is that for a lot of projects, you don't write a lot of code. And for the occasion that you do, the issues lies mainly in integrations and requirements/design cycle. I learned Vim and Emacs, not to write code faster, but to edit it faster. I've never been in a position where I said: I wish I could write more code.

In fact, most of my coding happens in an unfocused state. It's when I'm reading code (when there's a gap in the docs), learning a new system (libraries, platform, language), or designing a system (architecture, integration,...) that I give my full attention. The actual writing is mostly Edit/(Compile|Lint|Test)/Fix cycle that actually goes pretty fast in term of iteration and don't use that much mental energy.