My understanding of the regs is that giving more capacity doesn't really solve the problem because the problem isn't capacity, it's the recharging speed. You can deplete your battery on a straight and be fast but if the battery doesn't get recharged by the time you get to the same straight you're not going to be consistently fast. To be consistently fast the battery would need to be fully charged every time you want to use it. That's why you're seeing lift and coast. Not because they ran out of power but because lift and coast recharges the battery more. If the batteries would charge faster we'd probably have drivers complaining less about the cars.