Why are you talking to me like that?

I apologize. I was going for levity, not insult. It's easy, in niche internet subcultures like this, to fall into the idea that everyone outside the subculture all uniformly believes the same specific thing. I'm not immune. Many internet subcultures devote a lot of energy into collectively creating a hypothetical amalgamation of everything they personally dislike, then posting about how everyone else is just like the bad thing chimera. It's the most reliable way to drive engagement. Look how popular /r/ShitDumpPeopleSay style communities are in every online medium. I find that most normal people tend to have diverse, inconsistent, and largely unexamined beliefs about most things.

No one is more important or more valuable or more human, we are all the same, we all matter equally. We are our home.

I agree in spirit with all of this. "We all matter equally" doesn't mean "no one matters". I don't believe not individually "mattering" on a planetary scale means that humans don't "matter" at all: I see it as a rejection of anthropocentrim. I'm not the most important thing in the world. It came before me. It will be here after I'm gone. It wasn't created to service my personal desires. It's the only home of uncountable living creatures, older and more numerous than me, and they all have value too. I am not so much more important than every other living thing on this planet that destroying our shared home is acceptable just because I got what I needed out of it. Other things live here too, and because I don't have any more inherent value than any of them, I have a responsibility to be a good neighbor and steward of the only home any of us have.

I'm pretty far removed from taking Philosophy 101 so forgive my ignorance, but I wanted to speak on nihilism. I also haven't read a ton of any specific nihilist philosopher's work, so I'm going off the broad strokes as I understand them. Most people use "nihilism" in the way that most people use "anarchy": as an epithet that broadly means chaotic, disordered, or without purpose. Nihilism, like Anarchy, means a lot of specific and conflicting things depending on which particular author you're reading. My reductive understanding of the broad umbrella of nihilist philosophy boils down to two points. Point 1: Life has no intrinsic meaning. That's about as far as most people get. They hear that and go, "See, that sounds bad! [insert supernatural thing here] gives life meaning and tells us the one correct way all must live!" The ignored second part as I understand it is Point 2: Because life has no intrinsic meaning, we must create our own meaning. Some people hear that second part too and decide that, on the whole, it's not for them. They prefer to believe that something outside themselves gives their life meaning and defines how they should live. Fine by me! I'm not the philosophy police! I've just genuinely never heard of a self-described nihilist (outside of literal children) who claimed their own understanding of nihilism to be the first point, but not the second. The only adults I have ever seen use "nihilism" that way are using it as an epithet to explain what people they don't like must believe in order to be so evil.

It's the same way most people use Anarchist. "That person doesn't care about anything, and they just want the world to burn because they're an anarchist!" I'm a Marxist-Leninist, so have some significant disagreements with Anarchist political philosophy as I understand it. That said, I don't believe any self-described anarchists would characterize their belief system as "basically just, like, the Joker, man", even if that's what most people probably think. When someone says "the problem with society is there's all these anarchists that don't care about anything and just wanna fuck shit up", I don't think that's a very accurate way to explain the world, both because there aren't that many Anarchists shaping world politics, and the ones that exist wouldn't describe their own beliefs as "fuck everything! nothing matters!"

Coming back to nihilism, I think plenty of people can find the idea that life has no intrinsic meaning beyond what we make for ourselves to be freeing. They can know being their authentic self and doing what makes them happy is just as valid as anything else, and that they're not "failing" at life by not conforming to the mold that their family, or god, or society sets for them. A woman isn't "failing" at her "intrinsic purpose" as a wife and mother if she doesn't want to do any of that shit, for example. Any way she chooses to live is an equally valid way of being a woman. I can see why that might not resonate with some people, or that some might be frightened rather than hopeful at the idea of defining your own purpose, and I think that's fine. A philosophy is only useful if it helps you navigate your own life. People have different perspectives, and I generally think we should try to understand one another's differences rather than imposing our own on others.

tl;dr Nihilism: it's about perspective