Webcamoid is an app that I installed when I was trying out several virtual passthrough camera apps. Later when I found it lacking, I uninstalled it. But it would still appear as a virtual camera in video conferencing apps like MS Teams.
To fully remove it, I had to dig further:
Open the list of services in Windows and look for
Webcamoid. Stop and delete this service.
C:\Program Files\AkVirtualCamera.plugin folder.