The explanation is pretty simple and has been comented on quite a bit [1][2][3]: they followed the money. Catering to yuppies and affluent tourists is a much better bet in the 21st century than competing against Amazon and big box stores in the mass market space whith widespread financial insecurity in America.
[1]https://www.washingtonpost.com/business/2019/11/22/malls-are...
[2]https://www.cnbc.com/2019/12/19/how-amazon-changed-americas-...
[3]https://www.cnn.com/2019/11/23/economy/luxury-malls-holiday-...