The used EV can replace another dirtier car.

No, it can't. Its range is now so low it's no longer practical. Expecting people to accept a lot less is not realistic.

I see tons of first gen Nissan leafs with shitty range every day. And they still have some value on the used market.

No, you don't. What you see are the few people who are willing to make compromises to practicality that the majority of people are not. I would not buy a first gen Nissan Leaf with shitty range and neither would most people.

I'm quite sure I do. The Leaf is the best seller where I live and a lot of them are getting old : https://elbilstatistikk.no/

People don't drive that many km everyday and an old Leaf is an okay second car to quite a lot of people. Anyway, it's just an example because the first gen Leaf is an old car with a low range and a battery with a high degradation. If you think about newer leafs and other cars with more range, it's not really a huge difference if the car has lost some range over time.

I'm quite sure you don't. There are 2.8 million registered private cars in Norway. 68,873 Leafs doesn't equal "tons" in comparison:

https://www.ssb.no/en/transport-og-reiseliv/landtransport/st...