I think that wasn’t supposed to be taken literally but more tongue in cheek. The main point being that it belongs to some other party. But the cloud buzzword is fuzzy in description.
Back in the 80s, we used to draw network diagrams on the whiteboard; those parts of the network that belonged neither to us nor to our users was represented by an outline of a cloud. This cloud didn't provide storage or (useable) computing resource. If you pushed stuff in here, it came out there.
I think it was a reasonable analogy. You can't see inside it; you don't know how it works, and you don't need to. Note that at this time, 'the internet' wasn't the only way of joining heterogenous networks; there was also the OSI stack.
So I was annoyed when some bunch of kids who had never seen such whiteboard diagrams decided to re-purpose the term to refer to whatever piece of the internet they had decided to appropriate, fence-in and then rent out.
Ever since ‘cloud’ privacy took a nosedive