Best way to transfer data to a new iPhone?

Best is subjective - but will be influenced by if or where you have an available backup of the source device. While restoring a large backup from a computer may be quicker than restoring an iCloud backup over an internet connection, technically there is no benefit.

These support pages should get you started with setup of your new iPhone - and the methods of transferring your data from old to new device:

Set up your iPhone, iPad or iPod touch – Apple Support

Transfer data from your previous iOS device to your new iPhone, iPad, or iPod touch - Apple Support

Use Quick Start to transfer data to a new iPhone, iPad or iPod touch – Apple Support

If the donor iPhone, from which you are transferring your data precedes iOS12.4, QuickStart will not be available.

“Transfer” is rather a misnomer. In reality, your data and setup is merely cloned to the new device. Nothing is moved or removed from the original device.

An alternative is to restore either an iCloud or iTunes backup to the new device:

How to back up your iPhone, iPad and iPod touch – Apple Support

Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

Apps are not directly transferred between devices. For Apps, the transfer process creates a record of the Apps that are installed on the donor iPhone - and it is this record of installed Apps that is transferred to the target (new) device. For Apps that are still available for download from the App Store, the corresponding Apps are automatically downloaded and installed from the App Store.

David Illig wrote:

So I can't get an opinion on which is the best (taken to mean fastest) way to make the transfer. I already understand the process, know two or three ways to do it; I'm not asking how, only which, in peoples' opinions, is best.

Note to @LotusPilot: Thank you, but two identical replies are not twice as helpful.

I get the new phone every year and every year, I use Quick Start. It's quick, easy and painless.

My opinion........likely worth about as much as you had to pay to view this web page.......is that transferring from a backup on my Mac to a new iPhone is best for me.

Why? I prefer wired connections between devices when possible to transfer many Gigabytes of data because I think there is less to go wrong with this type of connection. But, that's me. Are things faster this way? I don't know....and don't care.

My neighbor swears by Quick Start because it is easiest for him. That probably makes it best for him.

David Illig wrote:

Best way to transfer data to a new iPhone?

Would it be a USB connection to a Mac that has a fresh backup of the old iPhone, or would it be to put them side by side and let it happen over Bluetooth? Thank you very much.

Whatever 3 methods you think is suitable for you Transfer data from your previous iOS or iPadOS device to your new iPhone or iPad - Apple Support

So I can't get an opinion on which is the best (taken to mean fastest) way to make the transfer. I already understand the process, know two or three ways to do it; I'm not asking how, only which, in peoples' opinions, is best.

Note to @LotusPilot: Thank you, but two identical replies are not twice as helpful.

David Illig wrote:

Note to @LotusPilot: Thank you, but two identical replies are not twice as helpful.

LotusPilot only posted one reply. The Forum software is set up to choose "Top-ranking reply" and then highlights the reply by displaying an extra copy (marked as the "Top-ranking reply") near the top of the thread.

Thanks, everyone. I can't delete my question, so just forget that I asked.