So why Gaming is YouTube dying? Well you see there has been a good long period of successful gaming videos made by popular content creators, making good entertainment and overall building a community. But this is 2017 now, and there has been a good competitor that has been around for a while and that is Twitch. Not only Twitch has let you watch the streamer do a playthrough live and come back to it later at any time. You get to interact with the streamer (only when live) and it is a huge deal for many viewers!
Lack of content creators being diverse and unique with the games has also been a problem in the last couple years. Most personalities and content creators are too similar and don't really stand out that much which makes creators fall into a pool of videos that other viewers are competing with.
Everything about the community is also getting stale and viewers could be maturing as well watching content that isn't kid or something new that interest them. Sometimes a change of genre for channels revive in many different ways.
I have more evidence on this YouTube video posted below!