I only have the perspective of trying to add gRPC endpoints/servers to a large existing project, and... it's a nightmare primarily due to gRPC's insistence on using its own threads and refusal to integrate into an existing mainloop. This has caused bugs galore.

(This is a 1M LOC C project, shoehorning in the C++ gRPC implementation. C++ has also added to the pain due to poor readability and maintainability of the code.)

FWIW this buf.io/ConnectRPC thing posted here does not seem to help our problems at all.