The McMurtry is a race car so it's not surprising it's that light. However it still pays a price compared to its contemporaries (go look at the weights of various LMP1 or LMP2 cars, even old cars like the Mazda 787B was ~850kg iirc). The only number I've found so far is "under 1000kg" so I assume it's probably quite close to that 1000kg number.

The weight of the batteries isn't going anywhere anytime soon. I expect car makers will prioritize range. I think the engineering to make an EV truly light like an old Integra Type R (1100kg) will be obscenely expensive and sacrifice so much on practicality it just won't be a viable product as a road car.

The car would be so compromised to be that light nobody will make the car, at least at an affordable price. You'll end up with a limited range, limited power, uncomfortable car for a price way out of line with what you're getting.

I think you could make a ~150kw-180kw EV pretty light, but considering the ongoing power pissing contest in modern cars I'm not sure how well it would market test.

So I expect the market will stick to heavy cars with big power because it's easier to build and easier to sell.