Earlier quoted context omitted.
The entire plan hinges on low cost high volume. That means reducing parts and complexity. Stainless steel body so no paint shop or variations to worry about, or paint maintenance, etc. removing steering wheel, removing glass roof, removing doors, and more. For high density you have the robovan.
Vehicles are dominated by the production costs of producing anything . You save surprisingly little producing smaller vehicles because the expensive bits are all the things you don't majorly save on like the production lines, the battery, the mechanicals, the wiring, the electronics, etc. Nicer interiors, paint options, and other consumer upgrades have extremely low marginal costs. They're pure profit for the manufac…
Just look at traditional USA automakers and why they are scaling up their vehicles. Bigger vehicles can justify bigger prices thus bigger margins. Even if the manufacturing price is not that much different.