What purpose do Downvotes serve

I see images that are funny or at least clever and I always see at least three downvotes on them, sometimes a crazy amount. I cannot fathom why someone would bother to express their disapproval of something like, say, a real pony that’s been photoshopped to be pink or purple. Okay, you don’t like it. Hide it or hide the account that posted it, genius. But what good does a downvote do? Does it stop similar pictures from being shown on your feed? It just seems like stupid passive aggressive thing a child would do. Isn’t this site 18+? (I have never had a downvote because I’ve never uploaded anything, so it’s not like I have a personal reason to be annoyed about this). Maybe make it so you can hide all downvotes for people who don’t want to be reminded that there are those dumb enough to be offended by the silliest most innocuous things.

Okay I actually found a way to hide downvotes by using the uBlock Origin’s “block element” feature. I just right clicked on a downvote icon and blocked it, now it blocks all downvotes on every image. Sweet

Such as people expressing their dislike of a picture?

Nah, on a serious note, there are really some mysterious downvotes indeed that downvote just for no good reason.
But, on the other hand, Manebooru, an MLP site like Derpibooru, launched in 2020 during the drama outrage, the said site has no downvote feature.

Ok, call me a pessimist (because I am, so does the OC:Downvote pony), but the original purpose of it is… having this feature is encouraging artists to draw quality arts, and use the score combining with comments for constructive criticism, and bad arts are less likely to be continued to be uploaded, keeping the MLP franchise name in high quality, and not looking too childish as what society stereotyped.

But so, nowadays, the there exists Manebooru, quality arts scores as always, still, but bad arts would remain low score (much like DeviantArt and Pixiv, only favs, no downvotes), so…

I don’t know if Downvotes (and dislikes) are still important these days, nowadays, you dislike something, you can just ignore it, or report it if it really is too offensive. Reddit doesn’t even show posts those are negative scores, but comments can still have negative score in order to detect the defect of the subreddit.

How dare you.

To show how bad an inappropriate the art is. And if you can’t handle that, why are you are here? It’s like removing the dislike from YouTube

Purely positive feedback options lead to false perceptions and to a generally unhealthy mindset.

If someone made something of questionable quality people should be able to express that.

Downvotes serves the exact same purpose as upvotes, anything you can say in favor of one is easily applicable for the other.