Downloading large files over LTE or 5G consumes significantly more power than doing so over Wi-Fi. How to Bypass the Requirement on iPhone (iOS)
Apple has historically been strict about this, but newer models and software versions (iOS 15+) offer more flexibility, especially for 5G users. If your iPhone or iPad won't update - Apple Support (OM) this update requires a wi-fi connection to download
The message is a common safeguard on both iOS and Android devices, primarily designed to prevent large system updates from consuming expensive cellular data or failing due to unstable mobile signals. While well-intentioned, it can be a major hurdle if you have an unlimited data plan or simply don't have access to a reliable router. Why Your Device Insists on Wi-Fi Downloading large files over LTE or 5G consumes