Yes, it has less utility than many other vehicles in many ways, but the bed length (5 ft) is longer than a lot of trucks I see on the road which enables carrying certain kinds of loads that aren't easy in cars or trucks with very short beds as seems fashionable now.
150 miles isn't a ton of range, but it's 50% more than a first generation Leaf and those sold.
The Slate clearly isn't trying to check all the boxes, but every vehicle doesn't need to try to do everything.
Slate's 5 foot bed is on the shorter end of common bed sizes. Certainly shorter and worse on every other metric than the F-150/Silverado/1500 'short bed' so commonly seen hauling air in the US.
The Slate would be the absolute perfect truck for me if it had a 4WD option. Being RWD-only is the only thing making me unwilling to replace my Tacoma with it.
Very few of the giant pickups I see have mud on them.
These are two separate questions.
I off-road an average of once a month, specifically to reach my usual shooting spot on BLM-maintained land. I don't necessarily need 4WD for that, but it's a good excuse to turn it on anyway.
I “need” 4WD when it snows, since 4WD/AWD + snow tires = not being required to chain up when chain controls are in effect, and because 4WD > AWD > FWD > RWD when it comes to snow driving (especially here in Reno/Tahoe, where the snow/ice happens on hills and having more drive wheels is a strict improvement over fewer).