I work in cloud computing and it’s amazing to me how magical people like you think it is. Yes Google owns YouTube, but could still run out of resources if Google chooses, they are still at the mercy of their provider.

Services may be setup to dynamically grow but they are still consuming finite physical resources and would run out if the provider doesn’t expand those resources.

The cloud most certainly can lose data due to hard drive failure and other hardware issues; the services are designed to make that very unlikely, but cloud services also have disaster recovery options you must implement if you want to be truly isolated from a given hardware footprint.