Because you aren’t the first one here. Countless lines of software exist which assumes posix. People learned how to use computers and know the grep commands. There is documentation for posix in places where it needs to be. It handles important edge cases which were needed by some groups and that was formalized into a standards requirement.

So changing to the new thing invalidates all that existing value.

That’s not argument to never do anything new, but it’s an argument why for your UNIX-like OS should ship the standard boring thing instead of the shiny new thing in the base install.

Having ripgrep installed by default doesn't preclude grep also being installed.

Indeed. So why it should it come by default?

Have you used ripgrep? It's so much nicer for day to day usage! That's why it should come by default. Seriously, try it out, I'm sure you'll love it!

I'd say POSIX is sometimes overrated.

Example: https://github.com/mpv-player/mpv/commit/1e70e82baa91

Anyway, I don't see any of that as a reason for not having ripgrep installed everywhere by default and as an argument for not using it.

It doesn’t matter if it’s over or underrated - what matters is if you want to be compatible with existing code and documentation.

I wish C didn’t have strtok, but it’s too late.

I don't specifically want to be compatible with it, no. I mean if ripgrep works for my needs - I'll use it and won't worry if it's POSIX compatible or not.

Great. But we don’t need it in base.

That's what I don't necessarily agree with.