Why it is in general considered easier to determine the electric potential at a given point in space or at a given set of points in space due to a continuous charge distribution than it is to determine the electric field at the same point or set of points in space due to the same charge distribution?
Ans:
In the case of the electric field each infinitesimal element of the source charge makes a contribution to the electric field at the point in question. Since every contribution is a vector to find the total electric field at the point in question one must do a vector sum of the infinite set of infinitesimal vector contributions to the electric field at that point.