IKEA does that stuff kind of crazy, even if you do need tools to put the stuff together. They pack all the materials into one small box. . .cuts way down on the volume, even for packing up the car.
Still need a truck, SUV or big van for the big stuff, though.
Shipping & storage are the big things. Not only is it easier to ship ('cause it takes up less volume), but it's less likely to get damaged during shipping. I'm sure there's some labour cost savings as well.
"..content just being a developer", I'm kinda the same way. What I've realized is some people want to climb the ladder, while others are just happy to maintain the status quo. And the latter recognize the existence of the former more than vice-versa.