Do people like lightboards? You have to be careful what you wear, how you stand, how you move etc. so that you don't cover what you have written (see the video by the inexperienced USC professor where she wears a white shirt). As a result, most of the time you can only use a small part of the screen, like here:
https://youtu.be/6I48J7Lf4_Y?t=173
Bad for people who are watching your videos on a small screen (phone, old tablet,...).
Or you use low lighting and then walk behind the board, like here:
https://youtu.be/6I48J7Lf4_Y?t=266
Which is a bit annoying because then you have things (i.e. you) moving in the background all the time. Not good for visually impaired audience members and people with low-bandwidth connections.
I will keep my $50 drawing tablet, although I have to admit that it's much easier with a lightboard to point to things (on the other hand, with a drawing tablet, you can just circle the word that you want to draw the audience's attention to and then undo it when you continue).