Yeah, I think right now without parallel processing the Intersect Solids component checks intersection with every other geometry, meaning N geometries must perform the intersection check N^2 times, quadratic complexity.
Tangent: There are spatial indexing algorithms that recursively subdivide space so that you don’t have to search all geometries for intersection which reduces this down the search time to something like log(N), on average (if I recall correctly). To give an intuitive example, if you subdivide a 1D line recursively by two, then searching for any element in that 1D line is equivalent to a binary search algorithm, which takes log(N) steps to find an element.