I'm not super familiar with YouTube terminology, is "YouTube Partner Program" something that applies to anyone who has ads on their YouTube channel? Seems to me something you need to apply to, and also only available in Canada, South Korea, Taiwan, the United Kingdom, and the United States which probably excludes more than 50% of popular channels on YouTube.
It seems to me that YouTube would serve ads on any channel, not just those part of the YouTube Partner Program, but the % revenue share isn't published for non-partners it seems.
Partners are everyone with monetization (revenue sharing) [1]. It's available in many many countries [2]. The countries you are listing are the early access to newer features like superchats, merch store, etc [3]
I'm not basing anything I say here on rumors or hearsay, I'm simply reading the content on Google's own websites regarding this, as I personally have no experience about it.
From the first link:
> I'm not a YouTube partner, so why am I seeing ads on my videos?
> YouTube may also place ads on videos in channels not in the YouTube Partner Program.
Doesn't this mean that YouTube is earning money from ads placed on videos where people don't get anything from the revenue?