1) That’s not how alternators work. Google “Lentz's Law.” The additional drain creates a magnetic field working against the alternator, forcing it to use more fuel to maintain consistent rotation. Just because it “spins the same speed” doesn’t mean it isn’t working harder (and the entire suggestion of being able to charge something with no additional energy burn is farcical)In the car is where that inefficiency doesn’t matter since the alternator spins the same no matter what electrical load you have going on.
Edit: Where I can see it mattering is on short trips where the phone doesn’t get charged up enough so has to be topped up with grid energy, though the strain there is minimal with such small devices.
2) “Minimal” sounds nice and reassuring until you realize there are… wait for it… a billion iPhones in the world.
Whether you believe in climate change or not, even a “minimal” additional usage of energy is extremely huge multiplied by a billion, leading to additional fuel burn, higher energy prices, more money in the pockets of petro-states like Russia, etc.
And that’s assuming it is minimal, which it is not (using a wireless, MagSafe-style charger uses A LOT more energy).