I think when ever you're comparing different 4x trucks you'll find different vehicles for different applications.
The H3 along with the entire hummer brand are off road vehicles.

Most of the other trucks made for the commercial market, are made for utility type work. carrying material or doing a specific task.

The H3 in trying to keep with the design of the original USGI truck was made to be what the Military wanted, a High Mobility Multi Wheeled Vehicle.
That said, It's not a tank or tracked vehicle, but can negotiate a lot of off road obstacles that other 4x's might have difficulty with.