Yes. Tableau would have to separate rendering from data select/filter/aggregation, especially because integrating with customer databases live is a key use case. Hence the built-in buffet of connectors/drivers.

It looks like with later versions they switched to kind of a hybrid approach (part-remote, part-local) with Hyper to reduce latency for interactivity.

> there is no sharing of the underlying data set for multiple projections across the same large data set

But that would require some kind of open standard for portability, no?