I found an estimate of annual expenditures of 3.25 billion, without content payouts, but with engineering/legal/moderation costs. As 2024 revenue I found back 36 billion from advertising & 14.5 billion from subscriptions. Forbes had an article where Google claimed to have paid out $70bn in 2021-2023 to content creators, this number probably includes subscriptions. In those 3 years youtube had an ad revenue of 89.5 billion, but I have no number for subscriptions. These are all very opaque numbers. Based on these opaque numbers, I’d guesstimate youtube’s profit margin at 42%, which I find excessive.

$36bn ad revenue + $14.5bn subscriptions: https://www.businessofapps.com/data/youtube-statistics/

$3.25bn annual expenditures: https://www.clrn.org/how-much-does-youtube-cost-to-run/

$70bn payed out to creators from 2021 to 2023: https://www.forbes.com.au/news/innovation/youtube-70-billion-creator-payments/

Edit, how I got to my guesstimate of 42%:
36bn ad revenue in 2024. An average of 30bn ad revenue in the 3 years prior. Estimation for the subscription income in those 3 years: 30/36 x 14.5 x 3=36 billion. 73bn expenditures & 126bn income = 53bn profit. 53/126 = 42%.