You're jumping to the assumption that surely YouTube's costs have to be lower than $36B, and that is not at all assured. They handle an absolutely gargantuan amount of network data transfer, not to mention processing compute. I'm ignoring the storage but even that at their scale is probably at least 1B.
"From Q4 2023 to Q3 2024, YouTube's combined revenue from advertising and subscriptions exceeded $50 billion."
Yes, network and compute is expensive, but when you are the size of Google the economics look a little different.
Are you insider, or have access to leaks I'm not aware of? YouTube profits are not public information (they are not broken down in the public fillings) so how can you say that confidently?
https://mannhowie.com/youtube-valuation
Think about it another way: Google would be only too happy to kill the site if it wasn't making money.