This is THE Catch-22! As long as mass wins, all vehicles will just get bigger and less efficient. There are smarter ways to make vehicles safe, but that will never happen..
The trouble is that once you have decent safety systems mass doesn’t actually make things safer, the opposite in fact.
Why weight makes things safer is only in a situation where one object is heavier than the other hitting head on. In glancing collisions many times the lighter vehicle is more survivable.
If 2 million pound gorillas smash there is more damage and likelyhood of injury than if 2 thousand pound gorillas hit.
By the logic most people use a semi is the only safe vehicle despite having no operator safety systems at all and sharp edges inside
The safest of all would be this because you could just run over houses, trees, semis
Needless to say we should have more of a Eurocentric focus on safety making cars lighter and safer to others and pedestrians, our vehicles fail Euro crash test’s because they are extremely deadly to everyone else but the occupants which is the wrong way.