Why is 3:2 better?

The extra vertical space is better for reading stuff, and looking at code. It also allows for smaller laptops with the same usable screen space - they don't need to be as wide.

I think you have that backwards. Wider screen formats allow for a proper size keyboard (and speakers) without having to have a massive palm rest and very tall screen.

I rock a 55" curved 4k TV (16x9) on my home desktop. To watch TV I move the desk chair and sit on my couch on the opposite wall. I can't explain how efficient this setup is in a small apartment.