Not speaking on whether the language should make this easier without an external library, but wouldn't https://github.com/sourcegraph/conc https://github.com/so

Not speaking on whether the language should make this easier without an external library, but wouldn't https://github.com/sourcegraph/conc https://github.com/sourcegraph/conc help in that scenario? It has context-aware and error-aware goroutine pools, seems like the exact fit for what you are trying to do. Although admittedly I dive too deep into your code.