BFS queues are not particularly difficult to describe, and deciding whether or not to do breadth or depth first is something I think about all the time. Frequently, for instance, in data access patterns, that decision can have a very big effect on performance. I can't agree that it's a random trivia question.

Edit: Ok, let me add some nuance here. I think we both probably agree that implementing a shortest path algo perfectly in an interview setting is beyond reasonable or useful. But I would expect an engineer to be able to have a discussion about it that shows me they understand the basic concepts and given google and a bit of time could relearn that. But without the complexity of shortest path I would not expect basic BFS to be outside of the scope of an interview. I guess that's just where I draw my lines.

Hmm, their difficulty is irrelevant. Your experience (like everyone's) is anecdotal and not representative of the immense fields of CS and SE that no one person can know all of, but could certainly look up.

If you are looking for a computer scientist, ask for one in the job req. No shame in that, it would save everyone time.

I added a sneaky edit (sorry!) that may address some of this, so I think we probably largely agree. I'm responding to a relatively specific claim, frequently heard by bootcampers and inexperienced engineers in web development, that foundational CS isn't useful, which my experience is somewhat representative of, though you are correct it's still anecdotal.

Yes, one can go too far in the opposite direction... "I don't need no book-learnin'!"