They way I see this, they felt like the major redesign was enough of a selling point.
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But above all I'm just not the biggest fan of this bulbous shape Pro has became this year, personally. Feels like we are going backwards and Air is more like it.
I though the Pros were hideous when I saw them, but after a couple of days I'm changing my mind. They are not pretty phones by any means, but I think they are as pretty as they can be given Apple's change of direction.
Someone said something on this forum a day or two ago and that stuck with me - the Pros are no longer the fashion accessory, instead they are the powerhouse that is no longer afraid of a more rugged look. I don't know if Apple is aiming for this ruggedness, but they are at least no longer prioritising appearance.
Before this event, a rich person at a fancy restaurant was always more likely to take a Pro iPhone out of their pocket. The Pros were aimed at the crowd that wants power but also at the crowd that wants aesthetics, a fashion statement.
This is why the Pros always had a gold option, with the exception of only the 15 Pro when the gold was replaced with natural titanium. The height of this "fashion" push was the 14 Pro, which had gold and purple.
The 17 Pro is the first version that only has three colours, it is the first version without the black and the first version to feature orange. Clearly Apple is repositioning this phone, not in terms of price-point, but overall look and appeal.
I think their plan for the Pro from now on is to attract customers who want pure power regardless of aesthetics. The Pro is going to be raw power and will somewhat resemble a Galaxy Ultra, while the Air will be more focused on aesthetics and will resemble the Pro iPhone of old. From now on, the Air is the new fashion accessory targeted at people who can pay any amount and use the phone as a fashion statement. The Air took that position from the Pro so Apple is free to make some different design choices on the Pro that they normally wouldn't do.