Which of these actions requires signing in as the AWS account root user?

Deleting an AWS account is a highly sensitive operation that permanently removes all resources and data associated with the account. Due to its irreversible nature and significant impact, AWS mandates that this action can only be performed by the root user, who has full administrative control and is considered the owner of the account. IAM users, even those with administrative privileges, do not have the authority to delete the entire AWS account. Deleting IAM users, creating an organization in AWS Organizations, and deleting Amazon EC2 instances are all actions that can be performed by an IAM user with appropriate permissions, demonstrating that these tasks do not require the root user.