Layers Panel Disappeared Completely

I see that other people have mentioned losing track of the layers panel, and people have rightly pointed out that it can be restored by View > Panels > Layers.

But in my install on MacOS 10.14.3, the layers panel has disappeared entirely from the list.

Same thing when I right click on the gray area above the browser. Layers panel doesn’t exist.

Unless I’m missing something here – QGIS is * functionally unusable without the layers panel *. I tried

restarting qgis
trashing the preferences
restarting the machine
reinstalling an earlier version (3.4)
but no luck!