This bit me today. I'm sticking with my iPhone 12 mini, and since it's now five years old, I decided to stay on iOS 18. But last night I got the prompt that an update to 26.1 was available and clicked the "update tonight" option without really thinking about it. I was tired, and I do have iOS 26 on a newer iPad, and for that moment I forgot that 26 is for my iPad and 18 is for my phone. Then I picked up my phone this morning and *#)?!(* here's all this Liquid Glass. Of course downgrading is impossible and getting a new small iPhone is impossible. I was happy with my setup and now it's gone. I don't think such a big and irreversible change should be triggered by a single prompt. Going from iOS 26 to 26.1 maybe, but not iOS 18 to 26.1. I'm mad at myself for this moment of inattention, but mostly mad at Apple for pushing their vision of big phones and distracting graphics. I did send feedback through the official Apple Feedback page, but it also helps to vent here.