Odessa is a city of less than a million people while 8 million are crammed into New York. The more apples-to-apples comparison would be Moscow (12 million).
Plenty of people are willing to trade space for location. They want to be in the center of all the action.
And prices are dropping rapidly as the city empties out because of Covid: https://www.cnbc.com/2020/11/12/big-drop-in-manhattan-rental...
La mélancolie, c'est le bonheur d'être triste (victor hugo)* You were sad in the past and you're remembering being sad
* You were happy in the past and you're a bit "sad" this time has gone or that you forgot what it was like to be X etc
I believe melancholy is the latter. You're not truly sad because you're also enjoying a nice memory but at the same time you're also a bit sad it's gone (hence the "happiness of being sad")