In all fairness, you see a similar “issue” with newspapers. Of course there are things that no online casino can compete with, such as the ambiance, the crowds and the glitz of vegas.
The core business however is a gigantic difference: the games can be played anywhere now.
Look, people will still want to go to Vegas, but its “unique” selling point is getting less and less unique and tougher to sell.
Perhaps we’ll start seeing the same with sports and attendence for stadiums now that the home experience is getting better and better.