According to media reports, the iPhone will launch iOS13 as soon as June. IOS13 adds a lot of new features that are very user-friendly, such as diablo mode, split screen, some UI changes, etc. In general, this is a huge update.
It is said that apple will only upgrade the iPhone 7 and above models, including iPhone 7, iPhone 7 Plus, iPhone 8, iPhone 8 Plus, iPhone X, iPhone XR, iPhone XS, iPhone XS Max, and iPhone 7 series below the iPhone will not support iOS13, These include the iPhone 5S, iPhone SE, iPhone 6S Plus, and iPhone 6S.
Of course, apple also gives reasons for not supporting the upgrade of these models. These models are too old and cannot keep up with the demand of software in terms of performance. If updated, the old models may lead to stuck and power consumption, which will further affect the user experience.