We often joke that ``the cloud is just someone else' computer,'' but that's not entirely accurate, because it's not just one computer, it's a network of computers, allowing the processes on it to continue running regardless of the status of any individual piece of hardware, or any single OS.
To throw everything on a single Raspberry Pi isn't really a cloud, even though it's offering cloud-like services.
OP says:
> "cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction."
> "When I read this definition, it seems like the authors are describing a managed cloud provider like AWS, GCP or some installable software like Kubernetes or one of the major hypervisors."
When I read this, I think of my good old webhosting provider. Giving me access to webservers with resources, and fully automated without any hassle. And when there is trouble, I can actually speak to a human being.
To throw everything on a single Raspberry Pi isn't really a cloud, even though it's offering cloud-like services.