Thats an ENTIRELY different setup than the op is looking at. Literally entirely different. Actual transfer case, direct injection engine, software and hardware update, much better build quality, etc. Not even a fair (or useful to the discussion) comparison.Newer ones had a selectable transfer case. My wife had a 2017 XL Denali with 2WD, Auto, 4 HI and 4 LO.
Ours also got great mileage on the highway for what it was. Better by 1-2 mpg than the 2021 Suburban with a 5.3 that she has now.