Two questions, please:
1) Does iOS 14.5 require that your Mac be running Big Sur if you are going to connect the iPhone and Mac together via USB cable for transferring data?
2) Does this also apply to the Image Capture app on the Mac?
My iMac is still on High Sierra. I have no intention to ever install anything newer than Mojave on this Mac.
If I install iOS 14.5 on my iPhone Xs, will I still be able to use Image Capture to transfer photos from my iPhone to my Mac?
Mark
iTunes
will prompt for an update to the MobileDevice framework for compatibility with 14.5. It does on Mojave, so Big Sur is not explicitly required.
That support doc addresses 10.11 or later, which implies that 10.13 should be ok, as long as the framework is updated.
To verify, do a version check with iTunes, Download Only the update .ipsw file, and then manually ask it to Update, and verify that it appears without protesting, or throwing up an error. It's a big download, but if you do decide to update, 14.5 is already at hand.
Image Capture really acts like more of a specialized app that interacts only with the media directory on the device, presenting the raw files with the human-readable names, and copying/deleting as desired. Not on the same level as what iTunes does.
Macs will always ignore iOS devices' file systems and require an app like iTunes to interact with a device in the pretty, sanctioned fashion.
But plug one into a PC, and they treat them as mass storage devices, and can read the raw file system, allowing manual manipulation of the media directory contents. That's basically what IC does, and insulates the user from the nitty gritty.
Unfortunately, Apple is less than clear about the Mac system requirements for each iOS version, but in practice, has been pretty flexible about keeping older versions functional with newer versions of iOS.