I-6’s don’t package well, that’s why they don’t like them. They also have a power-to-weight disadvantage. I-6 is also more diesel-like. The OE’s want these new engines to be more gas-like. A higher rpm v8 is more gasoline like than a slower revving I-6.
From the OE standpoint the engine doesn’t need to last forever. They want you to buy a new one in three years.
It’s not meant to be a tow vehicle. It’s meant to be everybody’s pickup with better mileage. It’s supposed to be “gasoline like” in how it drives and sounds.
You shouldn’t be towing 20,000 with any pickup. They build real trucks for that.