Teardown specialists Munro & Associates are currently taking a Hummer EV apart and have published a video showing how its battery pack is constructed. They guys seem pretty critical of some of the construction and materials used - and a lot of their points seem legit - but I think it's important to remember that this is a one-sided conversation. There's no one from GM to say why it's made like this. It does, though, score pretty low on their chart of gravimetric weight (Wh/kg) comparison, so I'd say there is definitely room for improvement. It does much better on the volumetric Wh/L comparison. However, that's not an especially important metric (in my mind, at least), since space isn't really a significant constraint.