Well I'd imagine youtube's infrastructure is very expensive. I guess they can no longer pretend the service they provide for free doesn't need to be funded. What did people expect?
Profiteering off of their established position.
Youtube PMs have OKRs
How do you know this?
> It represents 10% of Google revenue.
Revenue != profit. Storing zettabytes of videos across the whole world, with the massive CDNs required to be able to serve that whole world isn't cheap. I can easily see YouTube being among the most costly things Google do.