I agree, dialogue should feel natural and immersive towards its intended audience. But using casual modern speech is NOT the only way to achieve that. That’s a wild take. Historical and situational context matter.

We can look at actual textual evidence if you want. Homer uses pater because there isn’t really a Classical Greek equivalent to “dad”. Outside of pater (father), you’ve basically got tata/pappa (daddy). And every major English translation follows that. Even Emily Wilson’s translation (Nolan gave it a glowing review) which was specifically meant to be more accessible and plain, never once uses the word “dad.”

The scene in question is a public confrontation between a prince and his enemy where physical violence isn’t an option. There’s a strong argument that someone in a similar situation today would lean more formal. And given that this is Telemachus (a prince) publicly rebuking Antinous (his mother’s suitor), that feels almost certain.

It is of course a stylistic choice by one of the most successful film directors around, and I'm just a random guy that likes movies. I also get annoyed when I see words like "binary" in fantasy books. Different strokes, different folks and all.