This kind of fantasy microeconomics debate is silly at best, disingenuous at worst. We are talking about a company with $280B in revenue per year and one of the highest profit margins in America. How they spend that money is not connected to what is fair or what makes some kind of logical sense in your head. It's connected to whatever will increase their profits further.
All you are doing is laying down cover fire to support further advances by an abusive monopolist. YouTube's financials don't HAVE to add up. Google owns advertising for the entire Internet! The entirety of YT could be a loss leader just to suppress the growth of streaming video businesses outside of their control, and the Google monopoly would carry on.