… Eh? The predecessor to gRPC seems to have started internally at Google in 2001, and Google open-sourced it in 2015. In 2001, CORBA was all the rage; by the mid-noughties this had been replaced with SOAP, and maybe Thrift rpc in trendier places. I gather there was a whole parallel Microsoft ecosystem with DCOM and things, though that wasn’t my world and I don’t know much about it. But the point is that there hasn’t been a time where some form of RPC wasn’t in fairly common use since at least the early 90s.

The details change, and each one tries to solve the problems of the past (typically by inventing exciting new problems), but conceptually none of these things are _that_ different.