When should you actually put an API Gateway in place? That's the big question, right?

Hey everyone, been thinking a lot about microservice architecture lately. We're hitting a point where managing direct client-to-service communication is becoming a pain. Rate limiting, authentication, and request aggregation are getting duplicated across services. I'm leaning towards introducing an API Gateway, but wanted to see what others think. What are your experiences? When did you decide it was the right time to add a gateway to your stack?