Example author here.

I have to say this is a bit disingenuous. You pulled the segmented button component which in a real-world environment would just be a part of a library. You should show the part where it gets used. From my experience, how this ends up playing out in a real-world environment is that these things end up getting boxed into higher-level UI libraries that turn all this stuff into quick function calls.

The vast majority of devs aren't (and shouldn't be) writing their own custom components.