Try this with Android phones, tablets, and watches

While visiting family over Christmas I transitioned several iOS devices to more recent versions.

Here is what I started with:

Person 1, iPhone 12, iPad 7, Apple Watch 8
Person 2, iPhone 5, iPad 3, no Apple Watch

Leftovers from Person 1's upgrades:
iPhone 8, iPad 6, Apple Watch 6
These were used to upgrade Person 2's iPhone/iPad and create a watch v.6

I backed up Person 2's iPhone 5 and iPad 3, then reset the leftovers to factory original.

The iPhone 8 and iPad 6 were setup from the older versions backups.
The Apple Watch was setup from the iPhone 8. As it became possible all devices were updated to the most recent iOS versions.

This took several hours, most of which was waiting for software/data/settings to load from iCloud and for updates to load and execute. The iPhone and iPad were updated at the same time. Then the Apple Watch was created from the iPhone 8. Apple Watch in particular took quite a while to load and update. But I was doing other things while all that was going on.

When finished Person 2 had exactly the same Apple accounts, apps and logon passcode. I had to create a new iCloud password. The old ones did not meet current Apple requirements. Except for the fingerprints added to the phone and iPad and a few new Apple apps that showed and the faster processors up there was no difference in user experience. Apps were all arranged on screens and findable. Person 2 was VERY happy with the new iPad and phone. The watch he is not sure about. He has not even worn a watch since retiring almost 40 years ago.

I was an Android phone and tablet guy from 2005 to about 2017. Pretty happy with my choice too, but transitions to new devices involved manually loading apps, setting up email and storage accounts, and arranging icons. SMS phone message history never transferred. Apple does all that for you, including bringing over your iMessage history. Much nicer, and quicker.