YouTube is powered by the Advertising Video on Demand models. A number of other streaming services offer a freemium model, wherein the users in the free-tier (or the lower-paying tier in Hulu's case) are served ads.
The average cost per thousand impressions on YouTube is $2. Such a low CPM means that a video creator having a million views per video is making at best $2000 per video, an amount that would barely cover the cost for producing the video for content creators. Indeed the low CPM was the reason YouTube content-creator Jack Conte founded Patreon, for content creators to monetize directly from their fan-base.
Advertising Video on Demand is least sustainable for independent content creators of small-medium sizes, and content creators on Youtube increasingly rely on Patreon for driving revenue from fans. YouTube remains the biggest discovery engine for all content creators, but creators are looking towards branding and SVOD as means to monetize their videos.