These white noise, multi-hours long videos are directed to a very small audience, IMO. I see these types of videos as commodities, not anything particular unique. Personally, multi hour videos are hear not watched, unless they are a movie, documentary, show, etc.
There is a good chance people will NEVER click or if they do click, the AVD will be horrible. When someone plays a video for a few minutes out of several hours, the retention is very low.
I am not a big fan of gaming channels as a creator due to the overwhelming glut of them. But these white noise / background music channels are probably even tougher in my eyes.
Having said all that, there appears to be a few successful channels. Also, you should disregard what I say especially if you are very passionate about it. Because passion can cause creativity and perseverance which can lead you to success.