How about giving the option 'select objects' for users to highlight which objects they want to delete? My only option on iMac is to press F5, special, then select objects which deletes all objects. Please address this issue as quickly as possible.
This is now available in the 16.24 update, which you can get if you opt into the Insiders Program, by going to Help > Check for Updates (not available if you installed from the Mac App Store). If you don’t want to opt into the Insiders program, this will be released in mid-April 2019.
To select objects, you can click the Find & Select button on the Home tab of the ribbon, and choose the Selection Pane… or Select Objects.
Rick Lawrence commented
I think Excel 2008 was the last edition that had this feature and I complauned bitterly when I discoverd that this feature had disappeared in 2011. I used to be able to draw complex diagrams with a large number of objects for displaying dynamic representaions of complex models. Not any more.