Basically, yes! Browsers aren't the only clients (or servers) with limited capabilities, but they're probably the most important. Funnily enough, the biggest problem with browsers & gRPC isn't HTTP/2, its support for HTTP trailers.

I'm bemused by gRPC's status code system. It seems just as difficult to use as HTTP status codes, more or less, while also being less widely understood. If I were designing for myself, there would only be four error codes: maybe retriable and definitely not retriable, with an extra bit for whether or not the application returned the code explicitly. Sadly, we had to adopt gRPC's codes to make multi-protocol support work well. (Plus, I don't think anyone else agrees with my hot take on errors!)