Some are saying that the outcome is undemocratic in the US as the winner of the popular vote did not win the electoral college and hence the presidency.
Putting aside that it is unwise to insist that any non-proportional system is undemocratic, this misses a key element.
Candidates campaign based on the rules of the electoral system. If the US system was the winner of the popular vote becomes President, then the candidates may have campaigned quite differently and Trump may have won the popular vote because he would have spent more time in New York and California. Instead he spent most of his time on the Rust Belt states and this paid off.
The same goes in New Zealand in 1978 and 1981 when Labour got more votes than National. This was FPP so parties went for marginal seats. If it had been MMP then the popular vote may have been different as parties would have campaigned differently and campaigns do matter.
The Electoral College is an anachronism, but it is the system the elections are fought under, and can be changed if a constitutional amendment passes. But it was designed on purpose to make the US a federation of states, rather than a singular country with no states. It protects smaller states so that their interests are not lost to the larger more populous states. Now I’m not saying that is reason to retain it, but that is why it exists.