Well, my VW Beetle had metal inside door frames with an inset plastic-wrapped fiberboard panel. Maybe they are simply paying homage to their heritage...The ID4 a good looking vehicle and seems to be well put together. However, it's still a bit austere on the inside and some of the trim feels a bit cheap for a $40K-$50K vehicle.
Take a look at the inside door frames for example. Could VW spend a couple of bucks to cover and trim the bare metal door frame for this $40K to $50K car?
Look at a Volt's door trim compared to a VW ID4. Granted it's a minor detail but subtle details do make a difference!