It's just the matter of personal preference I guess... I have good enough completion for terminal with my current ZSH configuration. (I am not fan of auto completion even in IDEs and editors) One thing I need from few tools that I use everyday (terminal and text editor) is as low latency as possible, I get really irritated by all those few ms of lag that are visible after keypress, I don't know why. So any Electron app is no go for me from the start, so I decided to stick with Vim and Emacs. Only GUI editor that blew me away by it's performance is Sublime.

So long as you're down for 20 minutes of battery life.

You can have similar completion using zsh-autosuggestions, it is easy to configure. However, improving performance is difficult.