Can babies watch TV if not stimulating ?

Sorry but I cannot find the answer.

My daughter is 4 months old, I never let her watch TV and always turns her around when I notice her looking, but what exactly is about about TV? Is it the blue light? Or is it the content? Since some people on the internet say that it is ok to FaceTime grandparents, is watching the news for example bad for a baby? Since I would think it is a person talking and there is no flashing colours going on.

I of course understand that letting babies watch cartoons is bad, but what about a reportage or something like that?

Also, if it is the blue light that is bad, are projectors any different? Since apparently the blue light emitted is not the same. I saw some sensory videos for babies and apparently for 5 mins a day it is beneficial so I could maybe use a projector.