The problem is that all of those accounts that don't earn money don't earn money because they get no views, because they make videos no one wants to watch. I don't know the exact statistics but a simple Google search says that 3% of videos on YouTube get 95% of the views. Remove the top 3% of creators, you remove 95% of views.

The top channels get all the views because they're the only ones making videos people want to watch, and they're monetized because making such content is really, really expensive.

The problem is that beyond creators with "hollywood-like budgets", even just making 1 good video a week is a full-time job. Most creators are not looking to get rich or get massive returns, they just want to survive and pay rent. Which means any channel of any value has to be able to generate at least few thousand dollars month.