If you were to view their script and line delivery through the lens of a non-English speaking Korean audience, which this show was targeting, I think you'd find that this is a non-issue.

The same way that the vast majority of shows and movies produced in America for American audiences contain absolutely atrocious foreign dialog...

I thought that the casting & acting for the scene was on purpose to demonize the VIPs / controllers (westerners).

Evan costumes were horrible MardiGras masks would have even been a step up.

FWIW aside from the delivery working better alongside the original Korean (which seems appropriate for a series made for a Korean audience first), the dialogue was intentionally aloof and pretentious (while also being tasteless and crass). I don't recall the exact quotes but the actors pretty much stated that their instructions boiled down to channeling the spirit of the equivalent of a fedora wearing teenage 4chan user: stilted to make up for a lack of sophistication but also deviantly self-indulgent and crass.

You picked the worst acting of the series as an example here. The previous episodes actually did have superb acting. One huge difference to American and British shows is that nobody tried to be cool in squid game. They were acting like humans would.

Yeah, I agree the VIPs' acting kinda sucks. But everything else is uber good.