The top three percent of channels got 64 percent of all views in 2006. A decade later, the top channels took 90 percent.
The median views per video has plummeted to 89 in 2016 from 10,262 a decade earlier
Source: Almost No One Is Making a Living on YouTube | NDTV Gadgets360.com
There is now so much content on Youtube that it is very difficult for new channels to get noticed unless they have a promotional budget, outside connections, or they got very, very lucky.
Many of the top channels are effectively professional channels now, with behind the scenes staff and studio quality production gear (such as RED cameras).
A couple of years ago, I remember reading there was only one Youtube personality over the age of 40 in the top 200 channels (that being the very deserving Jon Schmidt of the Piano Guys).
At the present time, the article says the best odds to obtain views are to post videos in the Comedy, Entertainment, How-To, Style and Gaming categories.