API Gateway versus making direct calls between services?

hey everyone im thinking about the best way to manage communication between microservices. weve got a few options: throw everything behind an api gateway, or let services call each other directly. each seems to have its own pros and cons. api gateways offer centralized auth, rate limiting, and routing, but can become a bottleneck or single point of failure. direct calls are simpler initially but can lead to a tangled mess of dependencies. whats your experience? when have you found an api gateway essential, and when did you opt for direct communication and why