"It's not what you look at that matters, it's what you see." [Henry David Thoreau]
I think that Sumproduct needs quite a long runtime and too much effort to maintain statistics on larger lists. Pivot tables are sometimes too complex for the casual user - and they do not automatically update with a recalculation.
So there is a gap between these two approaches which I think I can fill. I offer several versions of macros to count frequencies or to add or concatenate entries or to identify maximum or minimum values for given combinations.