What made EV-as-an-industry financially feasible is the advancement in lithium battery technology, which by itself is fueled by the growth of the smart device industry. It's the parts that were changed, not the design of EV. Any details in today's EV design is optimization made for the sake of competition, and have nothing to do with the modern form-factor, if there's any. (It's still the same motor-connected-to-battery from (probably) early 1900s.)
The actual achievement should look like how Apple nailed the modern smartphone form-factor. Hardware-wise, LG did it first with their Prada phone, but Apple polished it with matching software and UX. Even though each component was already explored by others, Apple still had to come up with a working combination. That's an achievement.
Anyways, back to Tesla. Tesla didn't really achieve anything about EV. The real achievement of Tesla is car-as-smart-platform (which engulfs the entirety of self-driving). AFAIK, this is difficult on ICE cars due to mechanical and business reasons, but Telsa could avoid them by building on EV. Now this is a real new thing. IIRC, this is also what Elon has always been emphasizing. It's more than just an EV company.