Here are the specs for both models:
15-inch:
Height: 0.61 inch (1.55 cm)
Width: 13.75 inches (34.93 cm)
Depth: 9.48 inches (24.07 cm)
Weight: 4.02 pounds (1.83 kg)
16-inch:
Height: 0.64 inch (1.62 cm)
Width: 14.09 inches (35.79 cm)
Depth: 9.68 inches (24.59 cm)
Weight: 4.3 pounds (2.0 kg)
Yes, the 16-inch model is bigger in all aspects, and also heavier. This is fine for many people, who do care more about the power than the size and weight. It seems really to be a laptop for media professionals.
It is not a laptop for me. At this point, I need something smaller and lighter. I carried around a 4.4 lbs 15-inch MacBook Pro (the retina one) for years, and it felt heavy. These days, I am leaned more towards the likes of the MacBook Air and similar laptops.