I'm experiencing virtually the same problem. Except that my longtime android use has been buffered by a hand-me-down 5c and an 11 for a time, where both phones worked fine (syncs and backups) with iTunes installs on Win 10 in the near past (12.10.9.3, 12.11.0.26, and 12.11.3.17, iirc), but a new 12 mini just isn't being recognized. Attempted USB-A to lightning on 2.0 and 3.0 all over my system and the brand new USB-C to lightning cable on 3.1. 12 Mini has been on iOS 14.3 and 14.6, I noticed no difference wrt it being recognized.
My first attempts at fixing it were to try to diagnose with Device Manager, and whenever connecting the phone with iTunes (attempted with those 3 install versions) installed it would only show up as an 'Apple Mobile Device USB Composite Device' under the Universal Serial Bus devices and not interact with iTunes nor Windows Explorer/Win 10 Notifications. But after uninstalling iTunes and some minor registry wiping of Bonjour and AMDS, connecting the phone would bring up the notification menu where it would let me access the DCIM file and the phone would show up in Device Manager as 'Apple iPhone' under Portable Devices.
I really thought I was getting somewhere, but whenever i'd install iTunes or even another syncing program like iMazing afterwards, Device Manager would recognize the phone as an MTP device, Windows Explorer would lose access to DCIM, and iTunes/iMazing still would not recognize the phone.
After this I spent some time digging and this turned up lots of turingtest2's replies, mainly backing efforts to force the connected phone to recognize the correct driver (usbaapl64.inf), but this stumped me because in every iteration of my installing iTunes, it would never place a \Drivers\ folder containing usbaapl64.inf within c:\program files\common files\apple.
I could use 7zip to dig into the iTunes install exe for AppleMobileDeviceSupport64.msi and extract usbaapl64.cat, usbaapl64.inf, usbaapl64.sys, and usbaaplrc.dll and attempt to install the drivers, but this would just result in
"The folder you specified doesn't contain a compatible software driver for your device. If the folder contains a driver, make sure it is designed to work with Windows for x64-based systems."
And that's where I'm stuck.
I've also tried (to even less avail) resetting the AMDS service and doing an apple program deep clean, but aside from iTunes I haven't really used apple programs on this system. Win 10 Home 19043.1023 with a Ryzen 5 1600x on an X370 Taichi.
Edit:
c:\program files\common files\apple\mobile device support\ would have 2 subfolders, 'CFNetwork.resources' and 'CoreFoundation.resources'
c:\program files(x86)\common files\apple\mobile device support would have lots of folders, but no \Drivers\
