The person who benefits from a rule may describe it as simply how things work.

Arrangements that suit you tend to look like weather rather than decisions. When a rule reliably lands in your favour, there is little reason to examine it, so it gets described as the way things are done, or common sense, or nobody’s fault. The people it costs experience the same rule as a choice someone made. Both descriptions are sincere, which is what makes the disagreement so hard to resolve.

Take one arrangement you defend as obvious and find out who it is expensive for. Asking them how it feels from their side is quicker than reasoning about it from yours.