An iOS update can fail for simple reasons like low free storage, slow internet, VPN/firewall interference, or a partially downloaded update ...
Apple has just released for download iOS 26.0.1 in both OTA Update and IPSW links form. Alongside iOS 26.0.1 for iPhone, Apple has also released iPadOS 26.0.1 for iPad.
The company admits that users may notice temporary overheating or reduced battery life right after a major release, as the device completes background tasks like re-indexing and app updates.
Apple's iOS 26 introduces a new Liquid Glass interface but users report lags and glitches. Those dissatisfied can downgrade to iOS 18.6.2. Here is the process to move back to the iOS 18.6.2 interface.