HTTP/2 is quite featureful and provides most of the advanced needs that gRPC has; HTTP/2 is pretty similar to what we would make ourselves if gRPC used TCP directly.
Using HTTP/2 though also allows fitting into the wider web ecosystem of proxies, reverse proxies, load balancers/TLS terminators, and developer familiarity.
Using HTTP/2 though also allows fitting into the wider web ecosystem of proxies, reverse proxies, load balancers/TLS terminators, and developer familiarity.