> considering the increase in mass and height.

Most of today's cars are significantly less massive even if their size is larger.

Every new car is designed with pedestrian safety as a concern. Pedestrian safety regulations are the major reason all cars share the same profile. Designers don't have much leeway when it comes to the shape of a car because all the panels need sufficient cushion and be angled such that pedestrians are deflected, and there's only so many ways to accomplish that. So designers focus on what they can change, which is pretty much grills, tail lights and door creases.