Comment by asveikau

I don't think that's actually super common anymore when you consider that doing asynchronous I/O, the only sane way to do that is put it into a buffer rather than blocking at every small write(2).

Then you consider that asynchronous I/O is usually necessary both on server (otherwise you don't scale well) and client (because blocking on network calls is terrible experience, especially in today's world of frequent network changes, falling out of network range, etc.)