Why would someone refuse to update? Stolen iPhone comes to mind…
Edit: keep in mind, in OP’s video they are refusing to update even after their device is essentially throwing its hands up and saying “upgrade or I’m a brick now” and they prefer the brick for some reason. The performance of a brick is pretty bad…
This hasn’t been true for years. Since like iOS 12 or so it tended to be the same or faster. The problem is that the first time it boots after an upgrade things like photo reindexing happen and that didn’t use to give you a warning, so people would say it’s slower and never retract that statement when the problem went away the next day.
Older devices are def slower. I have an iPod Touch 5, iphone 6, iPhone 7, 8 Plus, SE 2020, 13 Pro, iPad 4, iPad Air 3, iPad Air 4. There’s differences with the older devices. They’re clearly slower. Starting with iPhone 8 Plus, it doesn’t matter as much.
Edit: keep in mind, in OP’s video they are refusing to update even after their device is essentially throwing its hands up and saying “upgrade or I’m a brick now” and they prefer the brick for some reason. The performance of a brick is pretty bad…