I don't think deeper gears increases payload in and of itself. On the 2023 F-350's, opting for the Dana 4.30 axle over the Sterling 3.73 axle, with the right tires, increases the GVWR by 400lbs. In fact, it's the only way to get the 11,900 GVWR package.
The Sterling may well be a stronger axle assy than the Dana. Many times our LDT mfg may have to use a different axle mfg to get the desired gear ratio.
However GVWR doesn't carry the the load in the bed from a truck camper/heavy GN or 5th wheel trailer hitch weight. Your still limited by Fords 7230 rawr which is the lessor of a tire/wheel /rear spring pack.
Fords F350 srw has over a dozen different GVWR's from 10000 gvwr on up to 12400 gvwr.....with the same 7230 rawr... regardless of axle mfg.
