For those still looking in the distance future, I was trying to solve this blurriness in an XR project with video streaming and video passthrough and couldnt solve it for a long time, never once did I think to change the AA from the HMD recommended settings to not be Temporal. I changed to FXAA and also tested MSAA and both solved my issue.
My project was in 5.3.2 so the issue carried forth.