Doing this kind of thing is a) rare and b) usually you have more things on your mind at the time, so you tend to be quite conservative and not think to experiment.
It doesn't really do anything particularly arcane (unless you count EBCDIC conversions) but it does things that are useful and often necessary that other equally-standard utilities can't. Isn't that good enough?
> Doing this kind of thing is a) rare
Probably not as rare as you think. Maybe it's not all that useful for writing applications, but for the quite large number of people who have to do provisioning (either bare-metal or virtual) and such it's a different matter. There's a lot to be said for tools that are ubiquitous, well standardized, and flexible.
$ apropos search
...
grep (1p) - search a file for a pattern
... $ apropos search
apropos: Command not found.
Part of the issue is that a man page is a reference. This is a necessary kind of documentation, but sometimes I want a tutorial and sometimes I want a cookbook. References are great for some things, but discovering new tools isn’t generally one of them. Obviously, you don’t have to write man pages that way, but almost all of the ones I see in the wild are.
Another part is that man pages as a resource have really atrophied in my experience. Lots of new CLI tools don’t have them at all, and lots of systems don’t have them installed even for older/core tools. The why is harder. I suspect that it’s a mix of tooling (e.g. needing to learn groff/troff to write them), search (your man pages aren’t indexed by Google by default like your GitHub readme), and culture. But I’m not sure.