Heard from a friend that if you have an older iPhone, you have to trade up for the iPhone 11. Cannot download the OS or it will corrupt the older iPhones.
It’s not a matter of corrupting older iPhones, your older iPhone will not download this version at all because it can’t use it. You don’t need to upgrade to an iPhone 11. This version iOS 13.X is compatible with the following iPhones, with varying abilities in the upgrades:
If I had any of the last five models, especially if I had not replaced the batteries in them, I would be seriously considering upgrading to a more modern iPhone. They would be abysmally slow in operation with the newer iOS and much of the upgrade would not work on them because they just don’t have the hardware in them to support it. It will load and give them some of the security advantages, but not much of the technical upgrades.
For iPads, the following list are compatible with iPadOS 13:
Again, if I were to have the loser models of the iPad, they still work fine with the current iOS or iPadOS, but if I were to upgrade, I would also upgrade the device, especially if I had not upgraded the battery in the device.