I haven't had an iphone in 4 years. but I remember apple account required to set up the iPhone. Android is the same. I cannot set up my android without a Gmail account.
I've bought a new iPhone every 2-3 years. You can definitely set them up without an iCloud account. The setup wizard assumes you have one and you have to click through a few 'no I don't want to' nags before you can proceed, but it's definitely possible.
If you want apps you still have to sign in with your apple id though.
I though setting up a new iOS device required an apple account and online connectivity.
Only online connectivity is required, an Apple ID is not. Of course, if you want to use apps you’ll need an Apple ID.