According to the official documents, "No-one can see or download the dataset." in shared dashboard. So users can export the summarized data. It seems that you can enable this function and it will satisfy your requirements.
Dataset cannot be downloaded. That is well understood.
However, that's not what I'm looking for.
At each of report, there's an option to export data, then there are 2 options whether to export the summarized or the underlying data. I'm looking for the way to disable (some or specific) user to export the underlying data from report/visualization.