Ask HN: It is 2023. What's stopping gRPC in browsers?

What is the status of gRPC in browser as of 2023? The documentation here[1] from 2019 states that there are two implementations but none works out of the box without a proxy in between the gRPC service and the client. It also mentions about Streams Specification[2] to be available in the browsers. On the page itself, many of the demos seem to work fine even on Safari. As of caniuse.com, it seems that the spec has apparently good support [3].

So what gives? What is holding back the possibility of direct gRPC calls from browsers without a proxy in between?

[1] https://grpc.io/blog/state-of-grpc-web/

[2] https://streams.spec.whatwg.org/

[3] https://caniuse.com/streams

EDIT: Typos