From my point of view;
There is always the privacy aspect of course, that people do not really know how you look, this is a personal choice if this is important to you, or maybe just appealing
Then of course there's the option to monetize from it, by having it being an "exclusive extra" people can tip for in privates maybe, that you take off your mask and reveal your face, or maybe in the future make it a big goal.
There are also the cons of it, as I see there's what Vixxen81 also mentions that in CB you can be asked to stop what you are doing, to proof it's really you that's streaming, with no real warning before it happens
and then of course some people just do not like visiting rooms, where do can't see how the girl actually looks.
I think that's what I can think of at the top of my head, there might be more, both pros and cons of course. I never tried faceless camming myself, so it's also rough giving exact predictions to it I guess