You raise a good point, but where would we stop? Should movies depicting medieval events use medieval English? It was the lingo at the time after all.

I suppose it’s just a matter of the audience and balancing legibility and plausibility depends on whom you’re writing for. For me, if Legolas was aura farming while Gimli rizzed up Galadriel while Saruman wants to hop on a palantir call that wouldn’t work but perhaps a day comes when that’s enjoyable for someone.

The market for these variations is controlled by IP law, not by demand for writing them or reading them. Emily Wilson’s controversial (for silly reasons, in my opinion) translation of Homer demonstrates what’s available in this genre.

Perhaps one day Gimli will rizz up Galadriel and Sam will say “bye-eeee” as Gollum falls into Mt Doom. One might even get to the stage where an LLM sits in place of the text and translates live into your own hyper-personalized idiolect or more usefully into that which will never take you out of the scene.

As an example, "Hitting it out of the park" has no business in a medieval setting.