nietzsche

Hey hey hey now, you take that back. A hedonistic life is plenty meaningful.

And needs no justification.
- Sounds that the kind of thing a GENETICALLY SUPERIOR ALPHA MALE UBERMENSCH might think.
  Those VIRGIN CUCK JEWISH WOMANLY PRIESTS want to keep all the opium for themselves! Dare to seize it from them!- Literally Nietzsche

Be Philipp Mainländer.
Likely be the most nihilistic and pessimistic, radical philosopher that ever existed.
Live (and cease living) accordingly to the very principles you advocated for.
150 years later...
People talk about the meaninglessness of existence referring to Schopenhauer, Nietzsche... anyone but you.
Prove the very meaninglessness of life by having people often forgetting your philosophy on how meaninglessness is the core fundamentum of existence.

Jokes aside, while I often refer to the famous Nietzschian quote about staring at the abyss (out of its mythopoetic and quasi-Lovecraftian value), I'm aware of how he's overly too "bright" (especially his hopes on some "Übermensch", hence, some kind of human betterness) to shade on my darkness.

That's why I ended up doing a personal, ranked list of pessimistic thinkers. At the very top of this list is Philipp Mainländer whose point is roughly that "life is of negative value, and that the will, ignited by the knowledge that non-being is better than being, is the supreme principle of morality". Then, there are also Thomas Ligotti, Peter Wessel Zapffe, Emil Cioran and David Benatar.

I'm likely a layman when it comes to philosophy because I don't really dive myself into the works of a given philosopher (my focus is quite spiritual, the only book I really got to read cover-to-cover was one about Lilith), still my mind is deeply invested in questioning existence without relying on others.

Partly due to anthropocentrism. AFAIK, there are few (if any) thinkers whose worldviews are non-anthropocentric. Anthropocentrism kind of annoys me, because one can just look up and see how vast and timeless is the universe compared to us, and there's no "space" (pun intended) for our fleeting hominid grandeur.

But I kinda understand why.

This perspective we have as tiny lifeforms on the surface of a planet, having Cosmos covered by the veil of a quite dense atmosphere, turns massive stars (such as Betelgeuse, which effortlessly dwarfs "our" Sol) into tiny twinkling dots and makes us think "guess we're center".

This perspective, where entropy is such a gradual and "slow process", numbs our senses from realizing how it's happening right now ("our senses deceive us", after all).

It took getting a chunk of metal into space in the 20th century and pointing it towards this corner of solar vicinity in order for us to see our own infinitesimality, still even Sagan ended up sugarcoating it and gaslighting himself driven by this irrational fear stemmed from biological wiring that fears any consequences that could emerge from realizing and accepting our own cosmic irrelevance...

It's a fear of Death "Herself". An irrational fear from lifeforms, because "She" won't only come inexorably, but She's already here, around, among and within us, and any attempt to sugarcoat this, IMHO, is just gaslighting oneself. I don't exist hoping for any hope in this regard: She's my hope.

Anthropocentrism kind of annoys me, because one can just look up and see how vast and timeless is the universe compared to us, and there’s no “space” (pun intended) for our fleeting hominid grandeur.
Circles of Control. There's nothing you can do to affect the constellations and there's nothing they can do to affect you, apart from twinkle from far away. Any philosophical framework that places them above humanity in importance may be accurate, but it won't be useful.
"life is of negative value, and that the will, ignited by the knowledge that non-being is better than being, is the supreme principle of morality".
(Disclaimer: not trying to start a fight, I'm just genuinely curios about your perspective of this)
I don't really accept that anyone truly believe this besides truly evil people, "truly believe" here being "lives according to the philosophy".
If this is the conclusion for people, wouldn't the "supremely morally correct" thing to do being to end as many other people as possible before ending oneself?
Life being meaningless because of the vastness of space and time also feels like it's just a matter of perspective; we're not significant from a cosmological perspective but why would that matter? We are from a human (/individual) perspective.
You probably don't matter in the perspective of even human history, but you matter a lot to the people around you, and might even have had a crucial impact on someone who was just a passing connection.
Heard of efilism or similar ideas? I wish the idea that life in general is not something we would wish on any planet was more popular. Life centric view is super dumb. Matter comes first and life is a random consequence of that. There is no intention behind life. It is not sacred. It causes a lot of pointless pain.

Just do it™