It does matter. Using channels makes control flow much more difficult to understand, but allows you to avoid wrapping everything in its own mutex (or RefCell) and local reasoning is easier to understand. There is also a difference in latency and cpu utilization, both of which still matter in io bound workloads. I honestly don't think it's one or the other but optimal usage is a mix of both depending on specifics of the use case. Channels are great for things that you want to be decoupled from each other but it needs to hit a certain level of abstraction/complexity before it's worth it.

Even folks who write modern go try to avoid overusing channels. It's quite common to see go codebases with few or no channels.