I've never been into face cams during let's plays or livestreams because I remember a time when that sort of stuff was considered rather goofy/narcissistic within the let's play community...this was back during the late aughts/2010s. Not that everyone who does it is actually narcissistic or anything, but...I dunno. My first reaction to seeing an example of it back then was kind of just a, "Really? Someone thought it was a good idea to obscure a good quarter of the gameplay with their own mug? I'm missing what's going on down there!"
The other thing is that I feel people just sort of throw face cams into their gameplay nowadays without questioning whether or not it adds anything. It's not like the majority of streamers/let's players who engage in this practice are great actors or anything. It's at its most distracting with stuff like VTubers, where these extremely colorful anime characters hog the bottom-left corner of the screen and consistently draw your eye. The fact that they're almost gyrating around half the time doesn't really help. Yet because of limited technology/budget, their expressions hardly change much means that there's actually not much to see. Despite "face" cams being such a huge selling point for VTubers, I would ironically prefer their content if the avatars weren't present.