And in all fairness, "stuff no one should ever need to worry about" is prime interview material for jobs. Though there's so many formats of technical interviews you never really know.
In reality, when I've seen this:
1. Shitty companies will ask you esoteric details like this that aren't relevant to your job, in which case you should avoid them anyway. It's usually from immature devs that just go down a laundry list of stuff just because it's "easier to grade". Note I'm not referring to Javascript "weirdness" that may seem esoteric but is actually pretty important to know. For example, anyone who has been programming in javascript for more than a hot minute should know `typeof null === 'object'`, because (a) nearly everyone hits this as a bug at least once and thinks "that's nutty", and then (b) if you don't know this you will be likely to write bugs in your code.
2. This also doesn't apply if you're interviewing for a job where you need to know those esoteric details, like the other commenter who replied who wrote a transpiler. But if you're just, say, a front-end web dev, yeah asking some of the nuttier details (especially all of the inherent type conversion rules) is sign of a bad company IMO.
I sure do wish I had the luxury to do that. How the times have changed so quickly.
That's pretty much why I detest the leetcode stuff that pops up even in games interviews. I'm going to be digging into decades old poorly documented legacy code to provide custom tooling for a studio's workflow. Why the hell do I need to know how to make NxN Bingo solver in Log(N) time on the fly? I guess if you gave me 20 minutes to refresh myself on dynamic progamming I could do it, but I made the "mistake" of studdying Unreal Engine/C++ trivia instead (which I've also had on other interviews), as well as real questions like what impacts and tasks I was doing at other studios.
But it's a circus out there and I just have to put on the makeup. I'm preparing long term to not have to deal with this, but I just need another 3 years or so minimum to stabilize myself and prepare my plans.