I am not really sure of the current set of rules concerning monetization of YT video boundaries are, however if you are using the video as a point of commentary under the "free use" terms you can make revenue from it via various means. Many of the content creators there make (better) money after achieving a certain level of viewership from which then the platform takes on corporate/company sponsors and perks. Some of the benefits are tangible goods they get to keep.
I am sure there are readily available terms somewhere on it and there are also many videos related to the content creation process. My own understanding of it being a LOT of time, hard work, skill, and charisma.