GM came up with the "skateboard" chassis almost two decades ago, and most EV manufacturers use something similar. The problem with a skateboard chassis is that its so integrated into the vehicle that minor accidents can render the battery unserviceable, thus "totaling" the car. Car and Driver wrote a report on this back in January, titled, "Tesla EVs, Even Mildly Damaged, Are Being Written Off by Insurance Companies." This really this needs to be factored into the calculations when determining the carbon footprint. Telsa announced in 2020 that they will begin integrating the battery right into the structure of the vehicle, so there is no end in sight to this problem, and in fact it sounds like they are moving in the opposite direction.
The design decision makes perfect sense; One of the primary metrics by which they sell cars is its range. The skateboard design is a compensation for lack of capacity and poor charging rates. Hopefully battery technology progresses rapidly, so that vehicle serviceability can become a higher priority in vehicle design
Bottom line is that this needs to be factored into the calculations when determining the carbon footprint.