The Nevada state and Vegas municipal governments kept jacking up taxes in the mistaken assumption that as the first casino town, Vegas had a pull its rivals lacked. Got to the point that for potential visitors, Vegas was more expensive than hometown rivals while also offering fewer perks, and this is before hotels, air fares and car rentals. So increasingly gamblers are opting for the hometown competition instead of the hassle of a Vegas trip.
I prefer Tahoe, anyway.