That's why we invented computers. To take care of the thinky-makes-brain-hurty stuff.
Which is great, if the objective is to get an accurate answer.
But that's not the objective of an election. The objective in an election is to get an acceptable answer - to elevate to power an individual or group, in such a way as to avoid further attempts to seize power by the losers.
This implies that accuracy is less important than transparency. An electoral system can get away with occasionally picking a mathematically sub-optimal winner; It cannot get away with it being difficult for the voters to comprehend why and how the winner was chosen.
Electoral systems don't need to be fair; They need to be comprehensible and transparent. The rules can get away with producing arbitrary results that are clearly biased away from public opinion; But they cannot get away with producing results that a typical voter cannot confirm for themselves to be in accordance with those rules.
The point of elections is not to accurately reflect the aggregate opinions of the voters. It is to avoid civil war.
That's why it's so incredibly dangerous for anyone to claim that there's widespread election fraud. Picking a clear and unquestioned winner is more important than picking the right winner (despite the obvious fact that routinely picking the wrong winner could itself lead to questioning of that winner's legitimacy).
The rules need to be set in stone well in advance of the voting; And the counting of the votes needs to be not only in accordance with those rules, but obviously and demonstrably in accordance with them, in a way simple enough for the vast majority of people to confirm to their own satisfaction. The choice of an equitable set of rules to begin with, is very much a secondary consideration.