An advantage of the present system that I have not seen discussed is that it reduces the problem of vote fraud. Stealing votes is easiest in a state dominated by a single party, the sort of place where the Republican poll watchers probably work for the Democrats or vice versa. With the electoral college system, there is no point to stealing votes in such a state, since the dominant party is going to get all of its electoral votes anyway. With a straight majority vote system, on the other hand, each party has an incentive to steal all the votes it can wherever it can.
Even with the electoral vote system, the problem still exists in any state where one party controls a large area, such as a major city, but the other has enough support elsewhere to make the overall result uncertain. I still remember, long ago when I lived in Chicago, being told that the reason the downstate votes had not come in yet was that they were waiting to see how many they had to steal to outweigh the efforts of the Chicago machine.