The HoloLens2 is excellent for in situ visualization. Both the field of view and resolution is sufficient.
If you just want to display 3D images somewhere above the patient then a 3D monitor is usable for that. However, stereopsis is only one of the many depth cues (you also perceive depth from lighting, motion, occlusion, size, texture, etc), so while using a stereo display improves depth perception, it is not a game changer. The proof for this is that despite the 3D TV boom in the early 2010s when stereo displays were available at a very low pricepoint at many sizes, using various technologies (including active glasses, passive glasses, and without glasses), it still did not get traction in clinical use. It is still possible that 3D monitors will make a comeback (maybe because you find some really good applications), but right now it seems that augmented reality headsets have more potential.