Every SSID is duplicated for every additional wifi adapter you plug in (it is hard to show this as SSIDs are semi unique and can be use to geolocate people (wigle.net)
For the status bar pop out widget, it at least tries to de-duplicate by showing the interfaces (wlan0/wlan1). This doesn’t happen for the view in System Settings.
Both of these approaches aren’t very good, I think something like Windows should be done where a drop down at the top becomes available to the SSIDs for each adapter:
Gnome:
