I prefer another CNCF incubating project, NATS. (nats.io)

It decouples the service addresses via a pubsub architecture.

So if I want service A to send a request to service B, then it is done by subscribing to a shared topic, there is no service discovery.

It kind of replaces GRPC and Istio.

I like the “static typing” and code generation you get from grpc so a hybrid of the 2 would be my preference.

I actually solved the code generation part for NATS though by using AsyncAPI (like Open API but for messaged based systems). Would be better if baked in.