Far as I know the Electoral College is working as the forefathers intended to keep one or two states from electing our President. If that was not the purpose, feel free to correct me.
The electoral college is working basically as intended. The question is if it is relevant today in the same fashion it was in 1776.
We are no longer a collection of States. Before the civil war we were "these United States" and loyalty law with the state. After the civil war we have ever since been "the United States" with a standing national army, ever increasing transients between the states, and the issue of loyalty to state before nation was killed on the battlefield. The State itself no longer elects Senators. The vice president is now a selection of the president. Political parties have a firm grip. And electors in the college are now all selected by popular vote. And electors are no longer expected act as a buffer between the electorate and the Presidency - rather they affirm the outcome of the election.
Much has changed.
So asking if the electoral college is still relevant is definitely worth considering. I thought it still helped protect minority rights, precisely for the reason you stated: you don't want a few big states dictating policy for the entire nation. But it was pointed out to me that without the electoral college, they wouldn't. The votes would be split, popular vote isn't winner take all for each state. Arguably the electoral college could result in the very thing it purports to defend against.
California
2012: 7.8mil for Obama, 4.8mil for Romney
2016: 8.7mil for Clinton, 4.4mil for Trump
Texas
2012: 4.5 mil Obama, 3.3 mil Obama
2016: 3.8 mil Clinton, 4.7 mil Trump
Neither delivers all their votes to one direction or another. Each citizen in each state gets to have a vote in the Presidential election. Currently, as a Republican in California your vote doesn't really count in the Presidential election. As a Democrat in Texas, your vote doesn't matter (in Oklahoma a vote for a Democratic presidential candidate has basically been a throw away since 1968). This creates regional strains in large states, as the eastern valleys and north Californians are relegated irrelevant by the population of the cities.
In Florida, half the time your Republican vote doesn't matter, and half the time your Democratic vote doesn't matter - the state is nearly equally divided. Same with Ohio, Iowa, Michigan, etc.
These "swing" states are all that matter in a winner take all election. In a representative election, the whims of a few swing voters in one state don't get to decide the entire outcome. This is reflected in voter turnouts in states in which your vote "doesn't matter" because its clear who is going to win.
And of course there is the basic question of representation. When the college was setup the disparity between the states was not nearly as extreme as it is today. That could serve as a reason why we need to keep it, or a reason why it should go. But the disparity in voting power is growing:
In Oklahoma, one elector is selected for each 403k people. We sit right in the middle.
In New York, one elector represents 520k people. 510 for Florida. 508k for California. 481k for Texas.
In Wyoming, each elector represents 142k people. 165k in Vermont. 174k in North Dakota. 207k in Rhode Island.
This means that when it comes to presidential elections,
someone in Wyoming has more than three times the voting power of someone in New York. As demographic trends continue to play out, this disparity will grow and grow. With the winner take all system, Wyoming almost doesn't matter anyway - as their 3 vote winner take all tally is more than made up by California's 55 vote winner take all (shutting out what would be 15-20 electoral votes for Republicans).
That goes the other way too - Democrats continue to flood into Texas both from south of the border and from other areas of the country. Trump won with a 9% margin, and that margin has been tightening. The change is not eminent, but similar issues exist in Colorado, Arizona, etc. As cities grow, the rural vote rarely grows as fast - potentially creating an issue for Republicans in this generation (at which point Republicans will be whining to ditch the system, and Democrats will praise the founding fathers for being so wise).
Overall, the system is a historic oddity. I'm not sure it has entirely outlived its usefulness, but I think a conversation about it is worthwhile. Currently, the Republicans won't want to see a change because they perceive it as helping them (and historically, the Republicans are 4/4 on winning the Presidency and losing the popular vote. Democrats have never done it). So as a practical matter, it isn't going to change anytime soon. And that's OK, messing with a basic tenant of our nation shouldn't be something done quickly.