I mean the answer to your last thing is battery technology.
I agree that battery tech is what brought about full EVs. I still disagree that the Prius did.
Tesla and many others take advantage of both of these things happening to great success.
Could you please name a just couple of the "many others" that successfully implemented the new battery chemistry into their cars? Actually just one other would do. I apologize if that sounds rude it's not my intention. I can't think of a better way of wording this.