I think Apple’s reasoning behind this decision is the idea that most iPhone buyers already own a tablet, laptop or smartphone and thus already own at least one USB-A, USB-C, or USB-micro charger and at least one or more cables, or can charge via USB-A or USB-C on their desktop or laptop computer.
And while there’s obviously numerous reasons why charging with a 18-20w wall charger would be superior to most of the solutions I’ve mentioned above, I would agree with Apple that only an insignificant number of consumers in the market for a new iPhone do not own any of the devices, chargers or cables that would partially or entirely be enough to charge an iPhone at 5W charging speeds or more.
By only providing a USB-C to Lightning cable, Apple is not forcing you to buy a new charger. It’s forcing you to use one of the chargers or charging capable devices you already own and providing you a cable should you get a USB-C charger in the future or buy one from Apple.
However, the reality of the smartphone market is that most people think they need fast charging and are rapidly ditching all their old chargers for new ones. This trend effectively destroys any positive effects this USB-C charger omission could have had.
Only those without the disposable income to get a new charger are the ones who will use older, <18W chargers with their new iPhone.
I’d also argue that providing one half of a product, the charging cable but not the charger, immediately signals to the consumer that something is missing or incomplete.
Despite any greedy or altruistic intentions Apple might have had with this decision, the end result is inarguably that most new iPhone buyers get a new charger with the phone or buy one a little later, adding another $19 on top of whatever $ the iPhone cost.
The fair thing to do would be to have Apple either donate all of the $19 to fight global warming or provide a gift card to new iPhone buyers to get a new charger for free while asking them to consider if they really need it.
But what Apple has done here only serves to remind more consumers to buy fast chargers and then add another $19 in profits for every new iPhone sold as Apple for “some odd reason” didn’t lower iPhone prices after removing the chargers.