Can we implement bi-directional streaming with REST + HTTP2 as we could do in gRPC? I googled a lot and could not find any useful information!
When using REST, a request-response message pattern is typically used. In http/2, every request is a new "stream" - possibly a stream of "chunks". Both the request and the response can be sent "chunked" - in http/2 and http/3 this means that both the request and the response is a stream of data (only http/1.1 use the "chunk" term).
To use bi-directional stream between client and server, both the request and the response is sent as "chunks" (or data frames) without closing the request and response. There is however complicating factors around retries and idempotency that makes it worth to use libraries for this kind of communication.