Grep is from an ed editor command: global (g) to apply a command to all lines that match a regular expression, a regex surrounded by slashes (/), and print (p) to display those lines. Or g/re/p for short. This proved a useful enough operation that they made it a separate command in the early days of Unix.
ls, man, wc, ps, grep, …
instead of
list, manual, word count, process(es?), <actually, what the hell does that stand for again>, ….
You get used to it, and then it’s much quicker. And being able to write things down quickly is very important when you’re in flow.