If anything, a myth that persistent must have something behind it. (I've zero interest in FAANGs so I would not know if they do or do not really ask it).
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.
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.