Premature optimization is mostly an issue if I want to build a big machine and spent the first weeks on optimize and polish a tiny, not too relevant cog. But `

Premature optimization is mostly an issue if I want to build a big machine and spent the first weeks on optimize and polish a tiny, not too relevant cog. But `yes` isn't such a thing, it's a standalone tool. Here the UNIX philosophy "Write programs that do one thing and do it well" comes rather at play. Further, the optimizations it makes are not really complicated nor expensive to maintain. A page aligned buffer twice the most common page size is standard for basically everything where something is written or memory moves around. One certainly can argue that it is Ok doing it more simply as it still is more than fast enough for the common use case. But arguing that a bread and butter optimization, namely one that adds just a few dozen lines of code total while increase throughput by three orders of magnitudes, should not be made, or that it even points to a complexity problem, is not holding any ground IMO.