I noticed that we have both cameras and digital-cameras in our inventory of tags. I don't believe they are both necessary... I propose synonymizing them. The only kind of camera broadly used today is the digital camera, and in the world of IoT, if someone is speaking about a camera, it will definitely be a digital camera.
No. It's unfortunate that this action appears to already have been taken, as it was probably mistaken.
"digital-camera" tends to refer devices that are specifically alternative to film cameras, which generally means handheld and human operated. These would only infrequently be on-topic in an IoT context, and having lots of occurrences of that tag in external searches is likely to attract questions about general point-and-shoot camera support that have nothing to do with IoT.
In contrast, the kinds of cameras that are on topic in an IoT setting - streaming, recording, recognizing - while implicitly digital are essentially never referred to with that adjective. Adding it is quite unnatural.