In the viewport dropdown there's currently "Select Camera" and "Select Camera Target". But there's no "Select Camera AND Target". Most often when I need to move a targeted camera or copying it, I need to select them both, and that's currently very unintuitive. So much that I had to make a script for it.
Also double clicking EITHER the camera or the target, should select them both. This should also work for target lights. When copying a targeted light, the target from the two lights are in the same position, often making it difficult to select the correct one. Very annoying and would easily be solved with a double click to select both.