I'm not talking about the technical rules of legal moves when your king is checked. I'm talking about when there's checkmate and the victor and the loser are set in stone. Why can't I capture the king at that point? I can understand why you can't do so with a resignation because your pieces likely aren't near the king.
this reminds me of the hilarious rule in xiangqi where kings cant have direct line of sight on each other
probably implemented to prevent draws but in reality implies that the kings are anime characters that lounge around in their forts until they spot a worthy opponent, at which point saitamas theme starts playing and they rohan charge across the battlefield and gib their counterpart in a single blow