Vratislav Holub Apple phones are generally believed to be powerful devices with a long lifespan. This is possible thanks to the combination of timeless performance with long-lasting support, which usually lasts an unwritten 5 years after the introduction of the given model. However, it seems that at the moment Apple is trying to keep as many iPhones alive as possible, which is evidenced by the new versions of the iOS operating systems.
The list of supported devices does not change
When we look at the latest version of iOS, namely the list of supported devices, we come across one interesting thing. The system is also available on iPhone 6S (2015) or iPhone SE 1st generation (2016). Coincidentally, this is also the exact same list as for iOS 14 and iOS 13. From this, only one thing follows - Apple, in the current situation, for some reason cares that users of older devices can also enjoy full support.
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Pavel Jelic Why it pays to support even older iPhones
But why does Apple actually support iPhones as old as the iPhone 6S and thus allow its users to install the latest version of the iOS operating system? Unfortunately, the answer to this question is not as clear-cut as we would probably like, on the contrary. in the opposite case, it makes more sense from a layman's point of view. If Apple cut support for some older phones, it would at least partially force Apple users to switch to newer devices, which means profit for the company as such. But for some reason this does not happen and no one is quite clear why.
This year's iPhone 13 (Pro)
A satisfactory answer may be to build a relationship between Apple and the apple growers themselves. As iPhones as such already offer sufficient performance by themselves, which they owe to the A-Series Apple chips, they can handle older models (and not only) with newer, more demanding operating systems. After all, this can be perfectly seen when comparing Androids from the period of 2015 with the iPhone 6S, which still ranks among the most popular Apple phones ever, as it is still relied on by a relatively large number of users today. While competing models can more or less forget about support, you can still enjoy the possibilities of the iOS 6 system on the legendary "15Sku". But not all that glitters is gold. Even so, it is an old phone and it must be treated as such. Of course, a 6-year-old iPhone does not cope with some functions so well, or does not offer them at all (Live Text, Portrait, etc.).
By supporting even several years older Apple phones, Apple builds a relationship with the consumers themselves, who are then more likely to stay within the Apple ecosystem and eventually switch to a newer model. A subconscious feeling, according to which we somehow know that the latest iPhone can be a reliable partner for us for a longer period of time, can also play a role in this.
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Adam Kos 
They know that 5g gradually motivates everyone to switch to a newer model
That's simple, they don't want them to switch to Android. Older phones are owned by those with a lower income (a large market for used iPhones), or who simply don't want to spend 20-40 thousand on a new phone (I keep my iPhone for 3-4 years on average and the battery limits me more than the unavailability of some functions). Apple promises income from the App Store and services. In addition, sales of new phones are doing well for them, I think even better than they themselves hoped.
I bought a classic 13 and I also plan not to deal with anything for 4 years. Just replace the battery. I think Apple will take care and the power is enough for that time.