[edent]

This isn't necessarily about mathematical fairness.

The cake-slicing algorithm beloved by parents of waring siblings is a good example. "I cut, you choose" isn't guaranteed to give a 50/50 split. But it incentivises the cutter to act with loss minimisation as their goal. And most kids can intuit how fair that is.

There are cake slicing algorithms for increasing numbers of participants. But they become increasingly harder to understand for people who aren't experts in game theory.

So you're left with the problem of what causes the least complaints rather than what is logically fair.