Why does iCloud degrade the quality of my saved videos?

We shot hours of 4K video (3840 x 2160) with an iPhone 13 Pro Max. The phone was synched to iCloud, which automatically saved a copy of each video. However, when I logged into iCloud and downloaded the day's files, I discovered that iCloud had reduced the resolution of the clips from (3840 x 2160) to (1280 x 720), rendering them useless.

I'm not the first person to encounter this issue; others have posted similar complaints. The most commonly posted solution goes something like this: "Sign into your iCloud account, click on the file you want to download, and then hover over the download icon. An arrow will appear which, if clicked, will give you the option to download the unmodified original."

This oft-cited "solution" appears to be completely wrong, at least in my case. When I logged into my iCloud account, clicked on a file, and then "hovered over the download icon," no arrow appeared. There was no option to "download the unmodified original." Yet the videos on my iPhone are all 3840 x 2160, while the copies on iCloud are still 1280 x 720.

Every. Single. One.

I suspect Apple is doing this in order to save space, however I didn't sign up for iCloud because I wanted to conserve ones and zeroes. I did so because I was told it would be the fastest and easiest way to automatically save iPhone video files at the moment of capture.

Somebody, please. There's got to be a rational way of transferring video files from an iPhone to PC without having to individually move them, one-by-one, via the tedious and bunglesome facility of a USB cable.

Kindest thanks in advance!