"Tell me about a time you simplified a complex process." This isn't about using a new library. It's about rethinking how something works.
Strong answer: "Our deploy process had manual steps. I automated it into a single command, reducing deploy time from hours to minutes. Errors from manual steps dropped to zero."
Weak answer: "I suggested using React instead of jQuery." That's a technology choice, not an innovation.
The best stories show you identified unnecessary complexity that everyone else accepted as normal, and you eliminated it.