This. The extra mass is done about as well as it can be because it's all at the bottom of a car but jerk the wheel left and right it becomes instantly obvious that it's not a light car.

>ride quality worse

I think you are wrong here, in this exact point. More mass in the car frame makes ride quality better: you can have more weight in wheels (unsuspended mass) or more responsive suspension.

More mass means more inertia, which means you get more body roll and heave. To counter this, you need to compromise on your suspension design (essentially make it stiffer) to stop the thing flopping about.

There is some nuance here though: more mass does potentially give you options in lowering the centre of gravity which can certainly help. Putting the batteries in the lowest point is a smart design move from this point of view.

In general, I'm not saying you can't make a heavy car have a good ride quality, I'm saying you can make it ride well in spite of the extra mass it has to deal with. Adding more mass doesn't magically let you have a better ride quality.

> This is nonsensical. Nobody ever said "How do we make this drive better? I know! Let's make it heavier!"

It's not well phrased, but it is better for the vehicle, if the mass is the same, just closer to the ground. Center of mass is lower down.

Electric cars have this due to the big heavy "sled" of batteries at the bottom of the vehicle.