Some of the details inside protobuf in Java can be very convoluted, but they are also the result of intense benchmarking, years of experiences and a long tail with deep legacy support for old java.
Honestly I found the Java bindings to be way better designed and thought out than Golang. On a consumer level, the immutable message builders are fantastic, the one-ofs are decent compared to what Java can offer, and the service bindings actually provide a beautiful abstraction with their 0-1-many model. In Golang, if you only have to deal with Unary rpc they are OK I guess, but I really miss the immutable messages.
To be clear, I'm not talking about generated code or anything touching protobuf serde. Just grpc-the-library. Interceptors, retry policies, channels, etc.
Honestly I found the Java bindings to be way better designed and thought out than Golang. On a consumer level, the immutable message builders are fantastic, the one-ofs are decent compared to what Java can offer, and the service bindings actually provide a beautiful abstraction with their 0-1-many model. In Golang, if you only have to deal with Unary rpc they are OK I guess, but I really miss the immutable messages.