IMO in frontend world there are two important things: knowing how to search, and knowing how to determine which search results are useful as opposed to some Medium/blogpost fluff piece that is varying degrees of misinformed.
I was recently at an interview where they just asked me to name a list of CloudFormation functions I’ve used and what did I use them for. If I listed that on my resume as something I knew, it was fair game.
It is not a good heuristic if the person has two days to prepare in that it is very gameable.
It is important to be able to develop things _quickly_ in order to keep a job. For that, knowing how to search is indeed useful. But there are certain things that it is worth keeping in L1 cache.
I doubt that the laundry list of things that have gotten tossed out of W3C's HTML standards is one of them, as the grandfather comment implied.
A good heuristic for how good a web developer is is getting them to list every HTML element they know, including the deprecated ones like <marquee>. You would be surprised just how little elements they know, and more importantly, the semantic value of the elements. For example, knowing when to use <span> instead of <div>