I don’t disagree that prototype is rare in real world practice but, anecdotally, it has come up in ~20% of my interviews in some fashion. That’s enough that I would be upset if the person teaching me JavaScript didn’t also teach me prototypal inheritance.
In modern times that's something you can easily throw far back in mindbank, because in practice using ES6 it almost never comes up, and it's super easy to do a quick refresher on the semantics.
If I didn't know that interviewers tended to ask about it in frontend inteviews (because they totally do), would never bother to keep up to date with the semantics
