Just because replacement parts (and repair services) are available doesn’t mean every repair for every type of damage to the device is economically viable for the consumer. So, it doesn’t solve “the problem” in every case, but it does still improve the situation. Sure, every now and then phones would need to be replaced, I don’t think that’s something that needs to be stopped completely.

For example, I passed my iPhone 8 on in the family and it’s now 6 years old. Mainline software support just ran out (it didn’t get iOS 17) and the battery is on its last breath. Swapping the battery would cost 79,-€ from Apple. This is close to what the phone is selling for used (256 GB version), albeit with dying batteries as well, so a phone with a brand new battery would be worth a bit more I guess. So yeah, it’s not really worth it to get the battery replaced. But say it was 39,-€ instead of 79,-€, it would be a lot more viable all of a sudden. Not only would it be half as expensive as a used iPhone 8 - and buying used involves certain risks - the iPhone 8 would probably be worth more used because buyers would be willing to pay more when they then have to spend less on replacing the battery, which many people probably take into account when placing a bid on old phones. Add to that that full software support would probably add even more value to the used phone.

Of course, the iPhone 8 was I think about 969,-€ new in its 256 GB variant back in 2017. A 200,-€ phone probably would sell for next to nothing after 6 years. It probably wouldn’t even exist in the first place, as the manufacturer would likely sell a similar phone for more money if they had to provide 10 years of repairs and software support. But this article is about the carbon footprint of going through devices quickly, and not about offering dirt cheap phones.