Take out the Air's tapered-edge and it's actually 0.1" thicker. It's funny to see everyone complain about how "thick" the new Macbook Pros are when in reality, they're thinner than the old Macbook Air. Pretty amazing if you think about it.
2021 16" Macbook Pro
Height: 0.66 inch (1.68 cm)
Width: 14.01 inches (35.57 cm)
Depth: 9.77 inches (24.81 cm)
2008 Macbook Air
Height: 0.16-0.76 inch (0.4-1.94 cm)
Width: 12.8 inches (32.5 cm)
Depth: 8.94 inches (22.7 cm)
2021 16" Macbook Pro
Height: 0.66 inch (1.68 cm)
Width: 14.01 inches (35.57 cm)
Depth: 9.77 inches (24.81 cm)
2008 Macbook Air
Height: 0.16-0.76 inch (0.4-1.94 cm)
Width: 12.8 inches (32.5 cm)
Depth: 8.94 inches (22.7 cm)