Complaining that breadth-first-search is irrelevant to frontend dev seems concerning to me. The DOM is a tree; so are JSON structures; so are website directory structures; so are half the data structures you will encounter in most businesses (departments, categories, etc.). You WILL need to traverse a tree in a frontend position at some point. I absolutely want to know whether a frontend developer has a variety of tools in their toolbox for handling tree structured data - and ideally the ability to refactor between recursion (using the call stack), explicit stack descent (which will be depth first), and queue based descent (which will be breadth first).
That would be incredibly rare to implement a breadth first algorithm in front end work. I mean you could pick any question about the most obscure browser quirks would probably be more relevant.
