The gas engines have cylinder deactivation so if you aren't giving it much throttle the computer quickly deactivates half the cylinders. All of the 1500's have had this for quite a while. It feels even worse with the 8 speed transmission because you're in 7th gear around 38mph, then it kills off 4 cylinders and you don't have instant power. When you give it more throttle, it jumps back into 8 cylinder mode. I've driven commercial vehicles or manuals for the past 25 years so it was very noticeable to me.
If you don't notice what I'm talking about then just drive around for a while and feel when your truck switches gears and when you notice a slight drop in power and kind of a sluggish feel. That's when you're now using a 4cyl engine.
There's an easy way to cancel the cylinder deactivation while driving so you have full 8cyl power all the time. Ever notice when you gave the 1500 throttle while cruising along it seemed to have a massive power jump? That's because it not only dropped down a couple gears, but also switched all 8 cylinders back on.
I've got a 2018 1500 laramie and was going to upgrade to a 2500 because it wouldn't be as noticeable with the 6 speed. But in 2021 they gave all the gas engines the same basic 8 speed transmissions as the 1500 models (including the 2500 and 3500). I was just curious if they reprogrammed them to be more aggressive and not deactivate the cylinders as quickly.