I've fed a couple of those chicken-scratch sketches to nanobanana with prompt "Treat attached as a technical drawing of a bicycle. Produce photo-realistic image of the actual bike manufactured to that spec. Try to stay close to the input, where possible", and... wow, results are not great.

That was very fun, thanks for the link

No. But it reveals something about how this technology works, its statistical properties, from which you can infer the limitations.

Humans aren't machines trained on the entire stolen corpus of human knowledge. We expect that a human will do poorly at arbitrary tasks they have no experience doing – especially drawing, which many (most?) humans aren't trained in at all. The same isn't true of AI, where its proponents, priests and proselytizers have spent time, energy and billions of dollars attempting to convince us it can do anything better than humans.