Then the government needs to add those external costs to non-repairable phones to make the Fairphone competitive on price too. Unfortunately the vast majority of people will consider price first.
Yes and no, resell value needs to be acknowledged by people buying them just like people do when they eg buy a car
But you are right, and the government has done so to some degree, but they did it badly and I believe it also affected refurbished phones, making a phone pay for its production emissions over and over
There's more nuance than that. Total lifetime matters. If the first buyer keeps it 3 years, the next buyer may well keep it 3 more, or even longer.
Or the first buyer keeps it for three years then needlessly throws it away, or (more likely) shoves it in a drawer somewhere until it gets thrown away ten years later.