In my opinion showing yourself on camera, weather it be in a screen cast or just talking into the camera, helps you build Know, Like and Trust. But even more important, getting on camera as just a normal person and talking about your experience is much more relatable then having a professional polished video of someone in a suit and tie. Any small mistakes or imperfections shows how anyone can jump on camera and make videos and gets you even more trusted as someone relatable versus someone you need massive training to be.