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common advice is to have the top of your monitor roughly at eye level
Bear in mind that this advice is unchanged from the eighties, and speaks to working on VDUs.
The difference being that the focus point was at the top of the screen.
These days, focus tends to be towards the middle and lower half, and would suggest that having your screen a lot higher would be preferable.
YMMV, of course.
I would stack landscape too. With the webcam in the dead centre.