The last year for that bodystyle truck was 1998, and with the Cummins it was rated at 235hp/460 ft-lbs. It had a max tow rating of 13k in the right configuration.
Here's a cool old Motorweek review of 3500 trucks from this era for reference (note the built in step on the Ford cab and the tow ratings that could be outdone by some new half tons):
Payload stresses frame and suspension. Towing stresses the drivetrain. You need more cooling now because they tow a massive amount more now.
The modern version of that truck in your photo can be equipped to tow over 37k lbs, and they have a pretty rigorous standardized towing test now (which was only adopted for 2013 model year):
Here is some helpful info explaining how SAE J2807 tow tests are performed
fifthwheelst.com
So if you're designing a truck, and you know it needs to tow and haul and have some amount of off road capability, then you get what we currently have. They could definitely be less butch, but comparing an old truck that would really struggle to complete J2807 with it's much lower tow rating to a brand new truck with insane capability is kind of silly.