I think one major difference between spreadsheets and Jupyter notebooks is state/dependency graph. In a notebook, cells don't depend on each other. They can be run many times, and the order they're run in matters. This is one of the major gotchas with notebooks. With spreadsheets, they're generally deterministic. There is no notion of "cell order", cells are recomputed automatically depending on the dependency graph between the cells. This results in a pretty big user experience difference.
Yes in that it doesn't appear to use a dependency graph to track recomputes; it recomputes everything on a cell change (according to another commenter anyways). But the UX effect is still the same in that the user never has to think about cell order, and every cell is always consistent with each other.
