microservice communication: sync versus async. what are the tradeoffs

hey everyone, i've been thinking a lot about how different teams structure their microservices and the communication patterns they use. we've been leaning towards synchronous REST calls for simplicity when one service directly needs data from another. but, i'm starting to see the problems, especially with cascading failures and tight coupling. on the flip side, asynchronous communication using message queues adds complexity with eventual consistency and debugging. what are your real-world experiences? when do you find sync communication okay, and when is it absolutely necessary to go async, even with the added overhead?