Revelation 21:16 describes the size of the golden city of New Jerusalem.
I ran some calculations on New Jerusalem I will share. I think we have to assume that New Jerusalem is a cube rather than one story with a 1,500 mile high tower in the center or some other shape.
1,500 miles high times 5,280 feet in a mile = 7,920,000 feet high or 990,000 stories at 8 feet per story.
The base would be 7,920,000 X 7,920,000 or 62,726,400,000,000 square feet per story.
If there were one billion people living on the first floor, each would have 62,726.4 square feet of living space. The whole White House has 55,000 square feet and there are four residents living there.
With a billion people on each floor, 990,000 times 1 billion = 990,000,000,000,000 people. There would be space for 990 trillion people in New Jerusalem with 62,726.4 square feet each.
The population of the Earth did not reach 1 billion until 1802. In the history of the Earth even if you count the fictional cave men before God created Adam, the total number of people who ever lived does not approach one trillion. All of them could be housed in a tiny part of New Jerusalem.
I’m not Einstein so my figures could be off, but clearly New Jerusalem will not be a crowded place with huddled masses.