The attic was poorly insulated, and because of that, there were ice dams on the roof in the winter.
The deflectors present in the attic were broken. And, there were several missing.
After the leaks were sealed, the baffles fitted, we blew just over 16" of cellulose fiber to get an R-60 value. To make a comparison, to reach an R-60 value (thermal resistance), it would be necessary to put at least 22 in. of fiberglass.