Most video glasses have quite a small field of view... Are yours the same? So it's kind of like seeing a screen floating somewhere in front of you, whereas with the vr headsets you basically can't see the edge so it's a lot more immersive.
I expect that's the main reason you don't get nausea.
I have never experienced ANY nausea and I'll do flying sessions several hours long (though I do take the googles off repeatedly inside that window.)
Given my experience with sea faring ships, I doubt that I am one of those who will not get nausea, so why is my use case not a problem? Is the nausea just due to an uncanny valley of which my setup falls short?