There have been some tech demos along these lines - basically an LCD filter layer that turns black where the pixels are lighting up.
Last I saw, that opaque layer's pixel density was far too coarse (so it blocked too much or too little - it needs like >10x higher density than the highest density consumer screens out now), and every tech I've seen has had a fundamental issue with focus - we can project AR pixels at comfortable focus ranges with complex enough techniques, but nothing exists to project "darkness", so it's at an entirely different visual and focal distance as the pixels, and it never looks quite right.
On top of that, you can't really use it to make semi-opaque pixels - you can only darken, and draw brighter stuff on top. So even if you solve ^ all that, you still have to accurately track the world, figure out what's being occluded, and re-draw that along with the pixel you want to draw. Without blocking vision, so the cameras to do all this can't see exactly the same thing you see.
... so every AR headset just adds a pair of literal sunglasses behind it all to dim the world so things don't look quite as bad, and that's the best we have now.
In VR with a couple cameras, you... just draw a semi-opaque pixel on top. And it looks perfect.
