I worked there so I'm well aware of how it works. My point was sometimes they need to do a massive encode during peak, and having the cloud allows them to do that when necessary.
I agree 100%. The cloud is basically the only way to do massive parallel processing in a very short time window without the up front costs. But if this event is uncommon, you can do your massive encode on the cloud, and shut off the cloud resources after peak and go back to bare metal.
I think bare metal is simpler, and that simpler often means better, but there are limits to bare metal. Those limits are where the cloud can come in. You can (and many people do) use both.