I have the same problem. I have a work security requirement that all my data stay on my own equipment. I agree with the OP that trusting iCloud to keep your data secure is asking for it. If you don't believe me, just ask AT&T customers who had their data stolen. You have to work very hard to keep iCloud turned off and Apple from vacuuming up all your data.
I prefer to maintain the master copy of my data on my MacAir and just manually download it to the iPhone by USB. I've trying to sync by USB from my MacAir to my iPhone. Everything is the latest rev. Nothing works.
I go to the Info tab and check
Sync contacts onto myiPhonenamehere iPhone SE 2023
and
Sync calendars onto myiPhonenamehere iPhone SE 2023.
This formerly worked but it has stopped working. So I try where it says...
Advanced: Replace information on this device
During the next sync, information on this iPhone will be replaced with information from this Mac.
I click the two boxes for Replace Contacts and Replace Calendars. When I hit the Apply button it actually unchecks those boxes and starts the Sync. And, of course, the contacts and calendars are not replaced as promised.
Some years ago when iCloud was new, Apple stopped the functionality of sync'ing the most secure way - by USB. Then that capability came back. Apple clearly desperately wants to force people onto to iCloud. I suspect Apple is intentionally disabling the sync'ing by USB capability to force people to use iCloud so that their data is no longer private.
If so, BAD APPLE.
