Bigger does not make it safer, F1 and lower formula cars are made primarily from carbon fibre, for really one reason, safety, as in the case of a serious accident, the amount of energy in the accident needs to be used up, and to use this energy, it is used to delaminate the carbon fibres, as to reduce the amount of energy on the human driver....
There are no airbags, so making the car bigger was only there to accommodate the modern technology, if we went back to a simpler system, using vodka water instead of batteries, the car would be scaled down....
The drawback to this is now the car is actually too small for modern high def television, so what is we want? A better looking car we can actually see on 75 inch tv's or cars that fit the tracks and that can overtake where the track was designed for overtaking back when cars fitted the track and 4:3 tv screens??
Found this....
I'd argue the halo is the biggest safety feature. Utterly ironic it's saved some like Lewis from the other utterly idiotic safety feature being sausage kerbs...
Carbon is also used as it's incredibly light weight and strong.