And I never argued against that. I just gave you one reason as to why their phones are more expensive. Of course used is greener than new.
It's not inherently more ethical though. While it could be argued that more green means more ethical because you are trying to harm the planet as little as possible if you buy a phone that's been produced with exploitation and child labor in its production line you still end up supporting it when buying used because you are part of the second hand market that supports people buying those phones. People will take into consideration if they can ever sell their stuff again when buying something. Those things would have to be weighed against each other if you want to make the statement that used phones are also automatically more ethical.
Buying a used phone that didn't have those things in its production line and actively tries to avoid it would technically be the best choice.
But ultimately it's something the consumer shouldnt need to choose anyway. Regulations shouldnt allow for that to happen on the first place.