Why? If you consider Netflix without the cost of content creation, then less than 1 USD per month per user would cover the infrastructure cost just fine. Maybe cents suffice.
Youtube is just one big profit center for Alphabet.
And then on the flipside, YT has a much harder infrastucture problem than Netflix. There's probably like 1000x as much content (both new and existing), and much more diversity in what is being watched. That means 1000x more storage and transcoding, and far lower cache hit rates.
(I've got no idea of whether/how profitable YT is. Just saying that if you're trying to reason about it via analogy to Netflix, you've got the directionality wrong on both of the issues.)
YouTube: 20 billion USD profit in 2021 on 28 billion revenue
Netflix: 12 billion USD profit in 2021 on 30 billion revenue
There's a reason why people call YT a money printer. And I just heard they are trialling showing five(!) ads before each video now.
Alphabet does not break out YT's profits in their financial reports, just the revenue. So that $20 billion is just a total fabrication. Shame on you.
It's also not at all a credible number, because YouTube's split of the ad revenue is known to be 45%. It's literally impossible for them to have 70% margins like you claim.
Weirdly antagonist response.