As
@swathdiver stated above, these changes are driven by what GM perceives that its customers want.
For those of you who are over 45, think for a few moments what the typical full size truck (Tahoe, Yukon, etc.), now called 'large SUVs', driver looked like 25 years ago, and what the driver looks like today. For me, being 72, this is what I saw then and what I see now:
25 Years Ago:
Almost always male
Usually dressed in work gear with a baseball hat
Usually had the windows open, unless it was winter or unbearably hot outside
Design emphasis on payload carrying capacity, suspension compatible with construction site travel, and capable off-roading
Little emphasis on driver creature comforts, except for perhaps a cup holder
Today:
~70% male, ~30% female
~50% dressed in work gear with a baseball hat, ~50% either a male in a dress shirt and tie, or a woman in daily clothes
Windows mostly closed, regardless of conditions outside
Design emphasis on quiet interior, smooth ride, additional comfortable seating, fancy trim, and lots of tech
Prioritized emphasis on driver creature comforts, up to and including massaging seats
I'm not saying right or wrong between now and then, I'm just saying very significantly different. As such, it is logical to expect that the truck would evolve over time, as the customer/driver base evolved.