As the chart shows, the reverse would be true: if they’re advertising a 150 mile range you would be able to beat that considerably if you drove at 30mph.
Yes, because it's true. But who drives at 30 mph? Grandmas maybe. Not exactly target audience for a truck.
The peak efficiency is actually at 25 mph, not 30.
The guy who mows my lawn drives under 100 miles a day, doesn’t need a huge cargo capacity, and certainly doesn’t want to overpay for a work truck. I’d bet there’s a sizable market of people like that.