One of the most common rewards from loot crates in Overwatch were sprays. (It might have changed, but I doubt it.) You point your character at a wall, and look, you sprayed an image there! Amazing! And I don’t care and would not notice if the feature were removed entirely, not because it’s cosmetic fluff (which I live for) but because it’s cosmetic fluff that doesn’t matter to me in the slightest. If I could convert every spray I ever received straight into currency, I would do so. They hold absolutely no value for me.
The thing about cosmetic rewards is that they only work if they’re something you actually care about. I rarely intend to use the various cosmetic options introduced in Final Fantasy XIV, but they’re at least there; by contrast, many World of Warcraft cosmetic rewards only can be used for cosmetic transmog during the events in question, making them fundamentally useless again. So what about you? What cosmetic rewards have online games offered that feel utterly irrelevant to you, if not actively disdainful?