Name another purpose of the idea of "wrongness". Right and wrong are all about others - what they do, what they think about what you do, what you do when you see what they do and what they do when they see what you do and on and on.
"Values" are about authority and superiority - manufactured, rationalized authority and superiority - neither of which can exist without others. For one who wants to be right, defending one's choices is critical. It doesn't matter if it's to or from other people or "God".
Of course you have your own preferences and of course you are absolutely free to call them "values" and ride a high horse about, declaring other preferences wrong - but why would you? There can only be one reason and that's others. and I think you understand that or you wouldn't need to wave your magic wand, turn me into some kind of straw man you feel justified in burning at the stake. Right? I'm not telling you anything. I'm exploring nihilism. Of course, exploration isn't necessary for one who "has all of the facts" but this is the nihilism sub and it's what some of us do here.
Of course there's objective truth. I don't have to know anything about reality to know that it is what it is, whatever that is. "Are you under the impression" it's not?
Depression is a chemical imbalance. This is a fact.
It is not actually a fact. It is a theory and it is equally possible that "depression" causes chemical imbalances. Which would make more sense because belief doesn't "happen" in a specific area of the brain. It lights up as a neural network overlay on it, with tentacles terminating all over the place in the systems to which the belief is relevant which makes perfect sense because belief must affect brain function to be believed in the first place. And it also explains why one can have one belief in one regard and a diametrically opposed belief in another.
Reality does have a nihilistic quality. It's that bit about you not being the boss of anybody who isn't willing to subject themselves to you and it touches everybody. Whether they are trying to control someone or trying to not be controlled by someone. Reality gives everyone equal backing, with regard to their beliefs. It works the same way for everyone and everyone has the freedom to use the mechanics of it however they want. Why do you think there are wars? What do you think people are fighting about? They fight for either the control of others or an escape from the control of others.
Man is a control freak and the nihilistic qualities of reality are, in many if not most cases, his nemesis. All hatred is hatred of reality not doing what one wants it to do nor proving that what one wants is "right". That's nihilism. But some don't hate it. I love it. I love reality. I love being equal to every other bit of it. I love that the Pope is of no more value than I am and that I am of no more value than Charles Manson. I love that everything under the sun is a sibling to me. Most hate the very idea of it and resent that the sun shines on everybody, equally. I don't. You can rationalize that all you want - even call me delusional, if you want - but you can't change it because, nihilism - i.e. because you are not the boss of anybody. Reality runs this operation and most are at war with it because it doesn't show any preference. It "loves" everybody and everything, equally. And why wouldn't it? Everything is it.