Count objects when using Select-->Same, Select-->Object, and "Start editing similar shapes together" commands. Sometimes "Start editing similar shapes together" does not select all similar shapes; therefore, an edit made using this feature may not edit all similar shapes, unbeknownst to the user. However, if I know how many shapes I have, then I can confirm that all shapes are selected when using these commands throughout the editing process. This is valuable because confirming the count of selections builds confidence that edits are made to all objects. Likewise, it also saves the editor time by mitigating the need to count all selected objects manually to ensure that all objects are selected.
Yes, it would be very useful.
Also, but just for the sake of statistics, it would be interesting to be able to know how many objects and how many anchor points are in the whole document!
William Nicholls commented
The Info panel does not provide selection count. Selection properties would be useful too.
There is 'info' in window menu
Malcolm Reese commented
There used to be 'Selection Info' in the file menu (i think) - gone now, I used it all the time.