The clarity of a fragmented table without converting it into an ordinary table

My goal is to find the properties of a fragmented matrix such as the maximum / average number of non-zero elements per line.

To achieve this, force is to convert the fragmented array into an ordinary array:

MaxSpar[matr_] : = Module[{curr, ms = 0},
    curr = Length[Cases[matr[[k]], 0]];
Yes[curr > ms, ms = curr];
, {k, 1, length[matr]}


How can we do the same thing without using Ordinary[]?