I think you're confusing "obscure" with "bad" and there are some very good but not very well known handhelds out there. Also no one is making you watch, this channel is a hobby that I do for fun so I'll cover anything I want and if you don't want to watch it, no one is making you. There are a lot of other channels you can watch instead.
Yes, these handhelds do get reviewed often, but this is the first time I have seen this particular one. I don't think I have seen one with a 2 player controller whatsoever, so there absolutely is value to these videos. That is like saying people shouldn't review bad retro games if AVGN already did it. Others still do, and it has value because it is someone else's POV and perspective.