Most devs have never worked on Solaris, but if I ask you about solaris and you don't even know what it is, that's a bad sign for how competent a developer you are.

Most devs have never used prolog or haskell or smalltalk seriously, but if they don't know what they are, that means they don't have curiosity about programming language paradigms, and that's a bad sign.

Most competent professional developers do code review and will run into issues with their code review tooling, and so they'll have some curiosity and look into what's out there.

There's no reason for most developers to know random trivia outside of their area of expertise "what compression format does png use by default", but text editors and code review software are fundamental developer tools, so fundamental that every competent developer I know has enough curiosity to know what's out there. Same for programming languages, shells, and operating systems.