The lag/effort was/is far less than google if the info is right there, and I personally found I kept having brain farts where I'd temporarily forget what language the thought I was having was actually in, and could quickly touch base again by referencing the cheat sheet without bringing up the (often distracting) web browser...
Or for the ultimate in self-referencing cheat sheets, use:
https://duckduckgo.com/?q=ddg+cheat+sheet&ia=cheatsheet
This links to:
https://duck.co/ia/view/duckduckgo_cheat_sheet
I think this leveraging off DDG's goodies, part of their Instant Answers:
Also when the topic at hand isn't very google-able and the cheat sheet is the next most efficient choice.
But a lot of the time cheat sheets get useless fast.
To go "I want to refresh myself on X's commands and syntax", read over a short cheat sheet? Maybe