I've never understood it ever. Same as when you walk into a cafe/restaurant and the waiter/waitress shows you to a table right next to others (pre pandemic) even though they're probably told to do it, or a person or family sits at the next table when there's loads free. Or when someone sits near you on a bus or train despite empty seats. Or, and this might just be me, when you wait in a supermarket for your shopping partner to come back to you. You can stand near the most popular product or the worst deal in the history of the world; at least one person will sidle up and almost silently demand you move so they can browse through a product that they never buy. Worst for me is when there are 3 urinals and a bloke chooses the middle one. No way can you have a normal and uncreepy wee while he's there.