We always think of doing something for long term but we regularly spend a lot of money for short term happiness. I am not saying this for those who have a lot of money, but for those who don't have that much money, there is no need to buy an iphone for around $1200 to $2000 right now.
You have a valid point that those who have enough money can go for luxury items like expensive phones, perfumes and other such stuff. But those who have limited money to meet daily requirements must look for investment opportunities. I have an inexpensive smart phone (price around 200$ when bought) that I bought 3 to 4 years back and trust me it's giving me everything a smartphone should have. There are people in our surroundings who accumulate money to buy such expensive items, if they keep investing that money in Bitcoin (DCA strategy) then they will get good profit after few years. IPhone value goes down with time but Bitcoin value goes up with time.
Generally humans are naturally dynamic that alone implies that there is certainty of behaviorer differences, our actions and reactions but above all there is need for a scale of preference according their most pressing needs though a lot don't adhere to this which is normal in that people may tend to do whatever do like it should be rest assured to also face the prevailing consequences of their actions and reactions, personally with my current situation I can go such an expensive phone even if I have the money because in my own judgement I have more important things I would prefer do with such amount of money compared buying such an expensive phone, in life identifying one most important needs and working towards achieving them is the best, knowing what is right thing to do and sticking to them at any given time.