I have no concrete proof of this, but I disagree with you on the idea that it's Youtube losing money, I actually think it's Google.
The myth that Youtube loses money to this day is just that, a myth. For almost a decade now they were supposedly profitable, with a huge payout during Covid, but even years before that Youtube reported losses in the tens of millions, while at the same time giving out hundreds of millions to organizations like TYT for the journalistic excellence and so that they could teach other creators in the space to be like them. You know, journalistic excellence such as this:
More so, I don't think they'd be trying to launch Netflix like subscriptions and milking the platform if it was truly that bad, what I think is happening is Google is losing it's share of the market slowly and they're trying to pivot more to Youtube to make up the difference. Though Youtube probably also took a hit, as I know a lot of people are now getting ever better promotional rates from all kinds of search engines for ad rates. Things such as buy $500 worth of ads and get an additional $250 free, are now as low as buy $100 and get $250 free.
Edit: Also, keep in mind what Rossman talked about in one video, they were playing video ads on random website embeds no one can see instead of Youtube, which is what got them in trouble. That sounds more like Youtube has too much ad money they have to find random places to shuffle it to, not that they aren't getting enough. Probably also why they're making this change, so that they can actually place all of these ads instead of dumping them in places they're not supposed to.
