MMULT to pivot data totals rather than SUMIFS

I figured this out, for anyone who might need it. For me this was important because now I can completely escape pivot tables and format financial statements exactly as I want.

You create a matrix of the items that match one of the criteria, multiplied by the count, to get Count or 0. Then you make a matrix of the items that match the second criteria that is just 1 or 0.   Then multiply the matrices to get Count or 0 at each intersection of the two criteria.

=LET(
sold,{3;6;2;1;4},
item,{"a";"b";"a";"c";"a"},
color,{"red";"blue";"blue";"orange";"red"},
rows,UNIQUE(item),
cols,UNIQUE(TRANSPOSE(color),1),

rowmatch,--(rows=TRANSPOSE(item))*TRANSPOSE(sold),
colmatch,--(cols=color),
countmatch,MMULT(rowmatch,colmatch),

countmatch
)