grep is POSIX and you can count on it being installed pretty much anywhere. That’s not the case for jq.

Do people contain themselvs to a POSIX conformant grep subset in practice, or do you mean GNU grep that probably doesn't behave according to spec unless POSIXLY_CORRECT is set?

"Anywhere" does not include Windows environments, which are over half the work computers out there.

If a workstation has Git installed on it, which I’d think would be the case for substantial number of engineers out there (…not just software engineers), grep is there due to Git BASH.