Yes, obviously the world would not go on if we all had no possessions.

The concept in "Imagine" is not only some sort of nirvana though.

When I was younger, I remember I watched a movie about St. Francis, and I have even just found a clip where he gives up all his possessions. I am not saying everybody should do that. I am just saying people find happiness in different ways, and the rich are not always as lucky as they think they are, nor are those who want to give up everything crazy. Happiness is subjective.

That said, I am spiritual but not religious.

https://www.youtube.com/watch?v=Ev2d92_W47Y