Not sure that's true. Just a few days ago someone was commenting here how they were a frontend developer with a few years of experience, yet they didn't know what a for loop was. These interviews aren't about how quickly you can figure out the right data structure, they're about separating developers from "developers".
In my experience, all the questions I was asked were fair game - all of them were about implementing a toy version of a real-life feature (simplified for the time constraints of the interview). All of them felt like "yeah, a competent engineer should be able to do this".
There's no question that a competent, well-rounded programmer should know about these algorithms' existence and when to use them. But whether testing if said programmer can implement them from scratch during an interview... that's a million dollar question whether these questions provide optimal outcomes. Anecdotally, yeah, sure, I did these things. In S/370 assembler at that. But did I use 90% of them since then(and that was when Apple was the only FAANG in existence)? No. So I think the feeling is that this kind of interview tests not so much how good, or experienced, or what not, you are at programming but rather how desperate you are to work at that kind of company to spend a good amount of time memorizing algos and data structures you've learned and forgotten years ago.