Which of these is not a primary benefit of cloud computing over on-premises computing?

The option highlighting the choice of paying for racking, stacking, and powering servers is not a primary benefit of cloud computing. In a cloud computing environment, these physical aspects of managing hardware infrastructure are handled by the cloud service provider. Users instead benefit from cost savings by shifting from a model where they must invest heavily in physical server infrastructure (capital expenses) to a model where they can pay only for the resources they consume (variable expenses).

By leveraging cloud services, organizations can eliminate the complexity of managing physical hardware, which includes the costs associated with housing, maintaining, and powering their own servers. This allows them to focus on what matters most: their applications and services, rather than the underlying infrastructure.

The other options represent clear benefits of cloud computing. For example, trading capital expenses for variable expenses allows companies to budget more effectively. Eliminating guesswork around infrastructure capacity needs relates to the scalability and flexibility of the cloud, which can dynamically adjust to demand. Finally, benefiting from economies of scale implies that cloud providers can offer services at lower costs due to their ability to serve a large number of customers with shared resources.