My understanding is it is actually necessary in some drum scanning applications. I have no personal experience with scanning as it is not part of my workflow. I'm 100% analog and based on everything I've read, when making analog enlargements wet mounting serves only two purposes - (1) eliminating Newton rings, (2) reducing the appearance of scratches in damaged negatives if the liquid has the same refractive index as the film base. I've never heard of it improving sharpness or grain masking, but I'm no expert in fluid mounting so I could be wrong.

As for perfectionism, it has to end somewhere . Fluid mounting is just not something I want to get into. Even if I did, I would expect it to be problematic or entirely incompatible with masking, which I sometimes use.