If it were purely random it would generate rubbish.

Not necessarily, but even in the cases where that's true, there will be the occasional result that surprises (in a good way).

This reminds me of when I would be surprised by AI bots I coded up for video games. Yeah, sometimes they beat me, and their strategies were often a mix of RNG and heuristics so I was certainly surprised by their behavior on many occasions. But would I consider them creative? No. Would they fool some people into thinking they had creativity and agency? Sure.