Without quoting individual messages, I'll respond to some of the above:
WRT having a second "daily driver", while it's true that there are some "non economic benefits" to having a 2nd vehicle, those are more than offset by the "non economic costs" the biggest of which is where to park the damn thing at our new house. When we moved here in 2017 we had, between us, 4 cars, 2 trailers and 2 motorcycles. It was a real PITA. At our old house in Englewood we had a 100' driveway and an oversized 2 car garage and lived in a non-HOA neighborhood so parking wasn't an issue and we had plenty of room. Now we're in an HOA neighborhood that requires us to park the trailer in the back yard behind a fence, and won't let us gravel the entire side yard for parking (they would let us pave it, but not gravel. Yes, I know, HOAs suck, etc etc,) So space is not a trivial concern. Nor is maintenance, registration and insurance costs. And again, this is not coming from opinion, it's coming from my real world experience of almost 7 years. BTDT.
My point being, it simply makes no sense for me to have a 2nd daily driver. Wife doesn't have a regular job so if it REALLY comes down to a $$ crunch due to fuel costs, I can drive her CR-V (25 mpg) to work and let her have the big truck if she needs to run errands during the day. I also have 2 motorcycles and there's no reason I can't ride those to work if the weather permits (which it often does.)
In terms of MPG, it seems that there has been an overall increase across-the-board since my '04 'Burb was minted. Half tons seem to be turning out numbers in the high teens or even low 20's on the highway. 3/4 tons seem to be in the 10 - 15 range. However, given that my current average MPG on the burb is about 12.3 (per Fuelly, which I use religiously) I'm wondering if a modern 3/4 ton (say a gasser Ram 2500 or Silverado 2500) wouldn't be about the same or perhaps only slightly worse.
In fact, since Fuelly keeps track of things like total miles, cost-per-gallon and MPG I have a pretty decent way of calculating what a decrease of 1.5 MPG would do.
In the almost 3 1/2 years since I bought the Suburban (bought in mid-December of 2015), I've logged 45,678 miles on Fuelly. I have consumed 3,713 gallons of fuel for an average of 12.3 MPG (BTW my miles are adjusted to show "actual" rather than "odometer" since I'm running oversize tires. "Odometer mileage" is about 17% less.)
My total cost for that fuel has been $8190.17 which averages out to $2.21/gallon (I'm a miser when it comes to gas and I use Gasbuddy.com to shop around for the best price. I also use E-85 if the price difference is more than $0.70/gallon which is my calculated break-even point.)
Using those numbers, a decrease to an average of 10.8 MPG would increase fuel consumption to 4,229 gallons for a cost (using the same average price) of $9,347, a difference of $1157.00 n 42 months or $27.07 per month. Realistically, that's not bad and the extra capability probably more than makes up for it (another nice bonus of the 3/4 ton is a much larger fuel tank.)