I am not 100% sure whether Las Vegas fully closed its doors, but what I do know is that gambling in Las Vegas hit an all time high in the beginning of 2021! 
Vegas casinos got closed. If I remember it right, Vegas was one with the most number of confirmed cases in the US.
They are in-talk here in this forum section during the pandemic last year wherein their Mayor wants to open the casinos despite the large cases as former USA President Trump itself was in favor of the Mayor's plan.
People freaked out when they reopened their doors fully. It was crowded anyway, but who would have thought they will bounce back with an all time high?
People miss the entertainment part of their life. It's hard to fight mental stress during pandemic.