Comparing it by toggling on/off will get me: sorta-looks-3D and now-its-not-3d while the monochrome depth buffer visualization clearly shows what objects have depth, how far it goes, how strong it is…you know for fine tuning, which I guess is more relevant to reshade shader since there are lots of knobs to flip, but as I mentioned even vorpx has few that might be more clear this way like far/near fine tuning on z3d for example.
I am not saying there is a dying need for it, just that its a nice feature to have that I saw in other app.