If you are building your own home, read The Not So Big House:

https://susanka.com/not-so-big-house/

It is full of good ideas and is a beautiful book in its own right.

1500 sq ft can work fine for a family of four if laid out appropriately. I'm actually a bit surprised that 1500-2000 sq ft is considered 'small'. It feels like the average sized house around here.

If both parents work from home and need to go on video calls several times a day, that size can get tough.

Sure, but that's a ~3 year old problem, not one the article is referring to.