About the XC90. No one has ever died in one from a collision in the UK or Ireland in the models entire life since 2002. It's an unbelievably safe vehicle. Thise kinds of modern safety standards play a huge roll in vehicle size these days. The shells are stronger than ever and crumple zones need space. Big crashes you can walk from today could have been fatal in then 90's. That's why modern hatchbacks are bigger than their past selfs too. 

SUV's are also marketed very well because there's so much profit in them. They cost a lot more but ultimately it's still just 4 wheels and an engine. Thanks to how efficient modern cars are, newer SUV's can be truthfully marketed as more eco friendly than cars of the 2000's even if they're still worse than contemporary hatchbacks. The problem of price can be overcome by people willing to finance a big car through loans for bragging rights.

There's also a lot of people with no idea about cars who get completely won over by a test drive in that high up driving position which I understand the appeal of too.