I don't do this often but if my post can save a soul from making the wrong decision, it would be worth the effort. We're in September which is the period which Apple flood the market with their new toys and people make the mistakes of throwing away money every year on these items. Why would anyone buy something that'll be devalued in about 12 months time because around this time next year Apple will be releasing a new set of devices and an upgrade of what will be released this year. Instead of buying those devices now, you can use that money for something more reasonable by investing that money in Bitcoin. The price of Bitcoin is low currently which is another reason to make use of this opportunity to invest in Bitcoin.
Those that bought bitcoin and ignored the latest iphone during the period those previous model above (in the image) were launched have made a better financial decision and anybody thinking of getting the new iphone when you already have a perfectly working phone should rethink that decision and invest the money in buying Bitcoin. You'll be getting around BTC0.031 +/- which will be worth more in the future than the amount you'll spend to buy it while that new Iphone will lose value in the next 12 months. if you really what to get something relating to apple then buy their stocks instead of the devices (that's another means of diversifying your portfolio, if you think you already have enough Bitcoin secured for the future).
Just imagine the profits that would have been if those that bought the new iphone during the release date of those model above bought bitcoin instead. Avoid making same mistakes and choose bitcoin.
I agree with the OP, I've tried the look at the features of the new Apple device and the previous one, I've seen that there is no much difference really.
So if you already have iPhone 14, I don't see the need in getting latest version of 15. Especially when the one you're using hasn't gone bad.
So it's at best you invest that money,, especially on bitcoin because there will be certainly a return in investment after a while. But for the iPhone, immediately you get that device, it will start to diminish in value as the months counts.