How to copy the unmodified original of a slo-mo video file from iphone to mac

Hi, I have an iPhone 14 Pro (iOS 18.6.1) and a MacBook M4 (macOS 15.6.1)

When I airdrop a photo or video from iOS Photos to the Mac, the original file gets transferred, the file size stays the same on both devices.

However, when I airdrop a Slo-Mo video from iOS Photos to the Mac, the file size on the Mac is only about 60% of the original file size on the iPhone. If you don't believe me, try it yourself.

So, how can I transfer the unmodified original Slo-Mo file, short of using an external storage device (clumsy) or iCloud Sync (slow with several GB-sized files)?

I already tried exporting the unmodified originals to a new folder "on my iPhone", but this folder won't show up on the Mac if I connect the iPhone via USB.