As a trucker, I lived through all the changes. No driver ever wanted a cabover, They rode and steered harder, were harder to work on and most were very cramped inside for large drivers. Most conventionals were also cramped inside to so the could sit very close to the trailer.
This was all caused by laws that limited the length of the tractor trailer combination.
Through intense lobbying by many parties to change the law, it changed to regulate the trailer length and allow enough additional length to accommodate the safer and cheaper conventional tractor even with a generous sized sleeper.
Part of this was trucking deregulation which killed most of the old unionized class 1 trucking companies who used no sleepers because they operated on a hub and spoke system and employed road drivers that only operated over set routes between terminals.
These drivers were either sleeping in terminal dorms or put in hotels.
With deregulation , most freight was hauled from anywhere to anywhere, many times by owner operators who often slept in their trucks at truck stops or at customers waiting to unload.
In 1985 through 89 I was hauling long doubles down the NY Thruway. The length law still on the books was a maximum 112 ft.and I had a R model Mack conventional and was 117 ft. long but the state police were under instructions not to enforce the 112 ft. rule so to allow the longer tractors.
The old unionized trucking companies cared nothing about driver comfort. They all thought we made too much money and should suffer for it. Consolidated Freightways even experimented with a cab under tractor that sat completely under the front of the trailer. As you can imagine, ride was terrible because of limited suspension travel and visibility and headroom were very limited.