I'm fairly certain their career prospects don't hinge on whether or not they can perform a few job interview parlor tricks.
If I were to poll all my SE colleagues, present and former, and ask them when they last manually coded a linked list or b-tree - I can assure you the answer would not be "on a product we shipped".
B-trees with augmented information are very fast, and I know of no generic augmented B-tree. So I've contributed to a program that shipped a custom augmented b-tree. I assume the same goes for other types of augmented data structures. Is that so rare ? Or do most people simply not know how/why to augment data structures ?
If I were to poll all my SE colleagues, present and former, and ask them when they last manually coded a linked list or b-tree - I can assure you the answer would not be "on a product we shipped".