>Because from what I've heard some people argue that all truth is subjecte and thus worthless.
I think this argument is stupid. As in, English Major tier stupid.
Perception is our method of data collection, but denying that the data collected is actually there, that there really is an object we call a chair there, is silly. It's a twisting of language akin to all of the extreme leftist nonsense that has been sweeping the western world in recent years. I think the only reason that idea even exists is to make people feel good; to make them believe everything in the world conforms to their feelings; that if they feel it, it is true. It's about as arrogant a philosophy as you can get without outright saying that you're god.
When it comes to a non-overlord fuckboy's meaning behind nihilism, simply put, it means nothing we do matters in the long run. Everything will die, everything will end the same way, regardless of what we do.
When it comes to science, it is simply observing how things work out of curiosity. I don't quite understand how anything physical can have "meaning" beyond communicated messages, but existence is not conscious (which neither are we, but that's another argument), existence does not think, it just is.
For the comparison of nihilism to Zen Buddhism, I'd say that's not a very strong one. Zen Buddhism's philosophy of giving up materialism comes from the desire to have a happy ending: to reach enlightenment. On the other hand, nihilists see no enlightenment at the end of the tunnel.