Quick start data transfer for new phone vs from a backup?

I can't compare the two as I've only used Quick Start, but I can say that while it is possible in my mind that using a backup might possibly equal Quick Start, I can't imagine it being better. The iPhones that I setup using Quick Start were virtually identical to the previous phones that they transferred data from, including the Home Screen layouts (except for a few built-in apps that were new with the new phones) and the process was quick and easy.

I've done both and I believe Quick Start is absolutely better. All your settings will be moved to the new iPhone using Quick Start. Very few things don't transfer with Quick Start. You'll have to reauthorize your credit card(s) in Apple Wallet, but even your mail accounts will be ready to be used with Quick Start. And some apps, may require you to sign back in, but it's quick, effortless, easy and to me the way to go.

I think you got some pretty thorough answers here:

Upgrading to newer phone and newer apple … - Apple Community