My 1962 Chevrolet C10 had cowl vents, get on the highway on a 95 degree day and pull the vent lever and receive a blast of sand and leaves. The vents are clear after 30 seconds but I experienced this every spring.
That truck was reliable for my off road travels but the poor ventilation system resulted in the need to clean up when arriving at my camp site.
I replaced that truck in 1999 with a Dodge Ram without air conditioning, installing A/C in this truck was more reasonable than installing A/C in the old Chevy with the drafty cab.
If buyers wanted cowl vents, manufacture would find a way to offer them, as it is there is no room below the dash for that type of vent and people expect air conditioning.
In a modern vehicle you push the "Auto" button on the control panel and drive, consuming 1/3 of the fuel of those old non A/C cars.