Why does my i phone take long during update

Hello Princelazo,

Thanks for posting in the Apple Support Communities.

The time it takes for an update to download and install can vary based on several factors: network speed and the size of the update. This information is disclosed in If your iPhone or iPad won't update - Apple Support section: If the download takes a long time. If possible, you may want to try connecting to a faster and more stable network when updating your device.

"If the download takes a long time

You need an internet connection to update your device. The time it takes to download the update varies according to the size of the update and your internet speed. You can use your device normally while downloading the update, and your device will notify you when you can install it. To improve the speed of the download, avoid downloading other content and use a Wi-Fi network."

Best regards.