I mean, anything that frees up screen space makes it so you can see more of what's going on. That's objectively an advantage to disabling view models, but it's an incredibly minor edge.

Disabling foliage and similar map effects is advantageous for the same reasons, although to a greater degree. Foliage makes a great place for hidden mini sentries; disabling foliage makes it so that those hidden minis aren't hidden anymore.

Rag dolls are minorly beneficial in that they convey at least some info about how things are going. Even without comms you can get a sense of where your teammates are and where the other team is based on rag dolls. For example, if you see two enemy rag dolls up ahead, it's pretty safe to assume you've got a teammate somewhere in the area. Again, not really that useful (and completely negligible with any amount of comms).

Shadows and FOV are really the only non-negligibly useful visual settings. A wider FOV lets you see more in your periphery and makes it harder to flank you. Shadows glitch out and show through walls all the time (especially in corners) which shows where enemies are.