The pointlessness of arguing about it became obvious since the decision was already made.

pointlessness 是由形容词 pointless（无意义的）加上名词后缀 -ness 构成的名词。pointless 由名词 point（要点、意义）和否定后缀 -less（表示"没有"）组成，字面意思是"没有意义的"。 pointlessness 作为名词，表示"无意义、徒劳"的状态或性质。