Why not force the service to return a result?

[l-7-l]

Hey thanks for your great work, I was confused about how to do error handling.
Why doesn't ServerError implement some common HTTP errors like tonic does, currently if you return Result<T, CustomErrorType> in the service definition, the client will return Result<Result<T, CustomErroryType>, RpcError>, which is very counter-intuitive, especially when using tokio::try_join.
For example:

let (a, b) = tokio::try_join(
    service_a.get(),
    service_b.get(),
)?;
let a = a?;
let b = b?;

Like in the code above, you need to handle errors twice，isn't this a bit counter-intuitive? Am I missing something?

Best wishes for you，have a niiiiice day~~~