For any file created in Inkscape 1.2, previously in the "Layers and Objects" panel I would see a layer -- for example Layer 1 -- and objects in the layer were listed below it. 

Suddenly only layers are listed in the panel, the objects are no longer listed below a listed layer. Also, the arrow that used to appear in the panel to the left of a layer's name with which you could open or close the list of objects has disappeared. However, the objects still appear in a work space.

* Objects are no longer listed for all files I have created and new files.

* Objects are no longer listed even after removing and re-installing Inkscape.

I've searched this site and google for answers but cannot even find this condition being described. It's also more complicated.

Any idea how to get but to the beautiful functionality I had?

My system: macOS Monterey 12.4 and downloaded Inkscape from this site.

There's a new button to hide/show objects: 

https://wiki.inkscape.org/wiki/index.php?title=Release_notes/1.2#Layers_and_Objects_dialog

Gasp! I feel so embarrassed. Thank you!

No worries... new stuff always brings surprises.

Came here with the exact same question

Had also googled various terms for a while to no avail

Also now feel rather sheepish after seeing the answer. Thank you @TylerDurden that was great!