> My personal experience is that e.g. if your cdn can serve ads, but not video, then you lose subscribers.
Of course. But none of the major providers is suffering from that problem on a regular basis.
> if you lose money on every video a subscriber plays because of DTO costs, then you can't stay in business
These are public companies, and they have to report material risks (as CDN costs would be, if your claim is accurate) on their SEC filings by law. They're not reporting these as a material risk. They could be lying, I guess, but that seems rather unlikely as they'd be at risk of shareholder lawsuits and government prosecution.
Speaking of which, the Disney suit you referenced doesn't mention CDN costs at all. It mentions the "staggering" cost of content creation, which makes sense to me; content production easily dwarfs CDN costs. (https://storage.courtlistener.com/recap/gov.uscourts.cacd.88...)
(Also, as a side note, no large customer like these is paying retail DTO costs. Large or strategic customers get significant discounts on public pricing.)