Where do I see a list of core/theme/plugins for all my sites? And where do I update them?

Navigate to https://my.bionicwp.com/

Click "Wordpress"

Select the domain via "Search By Domain" field. You can see a list of all core/theme/plugins here.

There is an “Update All” button on top which will update the core/theme/plugins for all sites

Users can Update Plugin/Core/Theme Individually from here as well