Earlier quoted context omitted.
It's not. Not to that degree. Unix frequently espouses "do one thing", but how much "one thing" is is always open to interpretation. And it's never been quite as small as e.g. left-pad. It's more something like `printf` or `cat`, which do "print a formatted string" and "concatenate files" as their "one thing", respectively. Let me reiterate: The problem isn't "single responsibility", the problem is "single responsibi…
`cat` without any options support is possibly simpler than left-pad. I think the big difference is that very few people set their systems to trust and receive updates of `cat` directly from the developers of `cat` (and same for all the other standard tiny utilities). Instead, they rely on a Linux distribution to vet the developers' code and to regularly pull in updates. Maybe there's room for a similar model of distr…
https://github.com/freebsd/freebsd/blob/master/bin/cat/cat.c
Also, cat is kind of an important primitive for building a functional system that uses files as one of its core abstractions. It makes total sense that it would (a) exist and (b) be well maintained by an authoritative and reliable source.
Left pad it is not.