You're talking about different things - $20,000 is pretty close to the bottom end of new car pricing in the USA. If you want more economy than that you have to buy used, which I'm sure will be an option a few years after those $20,000 EVs are sold new.

And of course people are talking about "economy" relative to the USA, it's where half the people on this site live. Nobody is saying car prices are the same everywhere in the world, and that's not going to be the same with widespread EVs either.