After updating OS, Can't Import from iPhone Photos into Photo app of Mac OS Ventura...

What happens? Can you open your Photos Library but File>Import is grayed out? It's important if you can open the Library, because the library is updated and modified when starting a new OS version.

How are you trying to import the pictures? Do you use a USB cable? If so, does Photos pop up? Have you tried using the app Image Capture that's in the Applications folder? Do you sync your library using iCloud?

How are your Photos preferences set?

In Photos>Preferences>General,

Is "Use as System Photo Library" grayed out (indicating it is) or solid (indicating this isn't your system library)?

Is "Copy Item to the Photos Library" checked? (This is the default, indicating a "Managed Library")

In Photos>Preferences>iCloud

Is "iCloud Photos" checked?

If it is, is "Optimize Mac Storage" check?

Have you tried these first steps?

• Restart the computer (of course)
• Rebuild your Photos Library by closing Photos and re-launching by option-command-clicking the app icon.
• Make a new user and see if the same problem recurs with it
• Use another library if you have one, or make a small test Library with a few pictures in it and see if the same thing happens.
• Start in Safe Mode (different for different computers) This bypasses certain potentially disruptive processes.

           Start up your Mac in safe mode - Apple Support 

One of these steps may fix the problem, but their failure to work is also diagnostic.