Is it inefficient? Would it be more worthy to have two chassis designs, one for ICE and one for EV, to make it more efficient for the gas version? Would any hybrid drivetrain provide higher efficiency for similar build costs on the same chassis?

My point would be that they weighed a lot of design considerations and I assume this is the best they could get that meets all of them. Like others said, other commercial delivery vehicles don't have the same use case as this. Who cares about range when the use case for this vehicle is ~20 miles a day?

Everyone else isn't "doing it wrong", they're doing it differently, for different needs.

There's a wider meta point here which is always relevant: nobody comes into work planning to do a bad job.

I'd add the second point is: if you're not in the same field, then start with the assumption that the people who's work you're looking at had good reasons for their choices (and that it wasn't a conspiracy).