I grew up in a 2400 sq ft home in Los Angeles in the 1940s and have a 2400 sq ft home in Glendale.
Have a 1200 sq ft condo in Oceanside and can’t fathome anything smaller!
I have a 2,100 SQ’ home now and have five sons. Plenty of room for all. I believe it will be tighter when they are older, but we have a finished rec room in the basement that we never use now. So we have plenty of room.