Import to Photos app/MacOs is disabled/greyed-out even though the iPhone is connected
It seems that my iPhone were full in some way:  after removing gobs of photos and videos it is working to sync.  I did not see/notice any indicator of the memory being full and the Settings|General|Storage had said 8.7GB out of 16GB before deleting anything (now says 6.6 out of 16GB).  That is strange behavior.