I think some iPhones get botched with updates while others do not. Example: a few years ago I updated my iPhone 6+ from iOS 9 directly up to iOS 12, skipping iOS 10 and 11, and iOS 12 ruined the 6+. It instantly became so slow it was unbearable. Doing anything.
But others posted that iOS 12 ran pretty good on their 6+, so obviously my update got screwed up.
I think this is typical of iOS updates (including iOS 26). Some phones get hosed by the update while the same model of phone for someone else runs fine with it.
There doesn't seem to be any rhyme or reason to it and I doubt Apl knows why this is happening, but it definitely is a warning to heed: update at your own risk. It may ruin the phone (or not).
I wish more people did that. If, instead of updating from a garbage release to an even more garbage release, they went from the original version to a garbage release, maybe they would see the difference instead of forgetting how it ran.
If you don’t track battery life, for instance, progressive dips in battery life will not be as noticeable, especially if you have a larger battery iPhone with enough headroom.
Apple Pencil usage on my Air 5 (running iPadOS 15) incurs an immediate 20% penalty. It is immediately noticeable.
Likewise with performance.
I think that obviously some updates are worse than others. People have been strongly complaining about iOS 26 on the 16 series. The consensus was pretty much that iOS 13 on the Xʀ and Xs was fine. iOS 10 on the 6s is pretty much flawless. iOS 11 was widely considered garbage even on the iPhone 7 and 7 Plus, and on similar iPads. iOS 12 was pretty much flawless on the iPhone 8.
Some first updates are good, others not so much.
The difference with iOS 26 is that this was very predictable, imo. If you knew a little about what iOS 26 entailed and the redesign, as well as some later beta results, the battery life complaints were ubiquitous. Even on the GM people were warning that battery life just wasn’t getting better, that scrolling to the app library resulted in repeatable lag, etc.
Like I said, especially for those who are on MR and pay attention to this, the warnings were there.
“Apple was too quick in preventing downgrades!” No they were not. I mean, they were, but they did the exact same thing last year. It was to be expected if you were paying attention.
Fool me once and fool me twice…
This was predictable. Those who updated either knew and did it anyway or should have known.