Aerodynamics.

Of course there are other considerations like safety, maintenance, and ease of manufacturing but...

Maybe you’ve seen it: three lanes of midsize crossovers that could trade badges and nobody would notice. Those shapes are dictated by interior space, powertrain packaging, federal regulations, and production feasibility. But most of all, they’re designed for aerodynamic efficiency. When we started asking manufacturers around the country how that works, we realized that it’s not incredible that so many cars look so similar. It’s incredible that cars look different at all.

https://www.popularmechanics.com/cars/car-technology/a21272157/aerodynamics-car-science/

The Aptera goes too far, passengers? Function? Nah - aerodynamic though.

As for the EV1 - well, it is a real sin that it wasn't continued - what a different world it could have been.

Something to be said for modular parts interchangeability.

A la Johnny Cash's "One Piece At A Time"
https://youtu.be/Hb9F2DT8iEQ

Back when it used to wash, there was a sudden interest in rear spoilers. These definitely don't have rear spoilers.

I say again--proof that aerodynamics has nothing to do with today's cars. Was I right, or was I right?

I'd also say that aerodynamics in any vehicle on the public road would have had too much lift to be safe expecially on slick roads.

Not surprising, tho. The first guys at Kitty Hawk could tell you that aerodynamic near-zero-drag airflow above will result in lift below every time. The spoiler's job is to leave the forward aerodynamics alone while spoiling it at the end for better rear traction. An aerodynamic car would also have side skirts but in terms of lift, those would be counterproductive along the undercarriage (wind tunnel).

Forgot to mention fuel economy of combustion; today's designs look more and more alike because other designs didn't maximize fuel efficiency.