> Let's assume Norway would have the exact same system and parties like Romania. Do you think Norwegians would have been swayed by a an online ad campaign to vote a Russian puppet off tiktok to the last round?

> Maybe the education level, standard of living of the population and being a high trust society, is actually what filters malicious candidates, and not some magic election method.

My point isn't about filtering malicious candidates. My point is that a "top two advance to runoff if no one wins the first round" system often does a poor job in the face of a plethora of candidates of picking a winner with majority support.

Yes, there are many forms of elections each with their own pros and cons, and that is one of the main cons of that system (and of one round systems where the winner is whoever gets the most votes even if it is not a majority).

Consider an election with 11 candidates and where there is one particular issue X that 80% of the voters go one way on and 20% the other way. The voters will only vote for a candidate that goes their way on X. 9 of the candidates go the same was as 80% of the voters, and the other 2 go the other way. All the candidates differ on many non-X issues but voters don't feel strongly on those. They will pick a candidate that agrees with them on as many of those as they can, but would be OK with a winner that disagrees with them on the non-X issues as long as they agree on X. This results in the vote being pretty evenly split among the candidates that agree on X.

The 9 candidates that agree with the 80% that go one way on X then end up with about 8.9% of the vote each, and the 2 that go the other way end with 10% each. Those two make it to the runoff and wins.

Result: a winner that would lose 80-20 in a head to head matchup against any of the 9 who were eliminated in the first round.

Note I didn't say that the 2 on the 20% side of issue X were malicious. They just held a position on that issue the 80% disagree with.

Such a system is also more vulnerable to manipulation like what happened with TikTok in Romania, because with a large field of candidates with roughly similar positions you might not need to persuade a large number of people to vote for an extreme candidate to get that candidate into the runoff.