+1. I had a similar crisis when I was a “big fish in a smallish company”, I wasn’t learning, I wasn’t being stretched and felt like I was going to get stuck in this eddy. Move to a bigger company, be challenged again.
Advice for OP: what companies do you admire? Either globally or locally? Have conversations with folks at that company (LinkedIn is your friend in accomplishing this) and see what people actually working at these companies think about challenges and accomplishments at their employer.
Big fish in small pond still describes the need for room to grow accurately enough.