Nihilism is people pretending that they don't care about anything, because they think that people will think they are cool if they don't care. But the truth is it just makes them look stupid because everybody can see that these people are putting on a fictional act. Everybody likes you better as yourself instead of some fake personality. And if you have any kind of problem, you can work on this and fix it and make yourself perfect.
What makes us great is the things we care about. We care about good and important things and this is what allows us to do great and important work for ourselves, for our families, and for all of society. Everybody that has ever created anything beneficial to the world, like a new technology or piece of art, is because they cared very much to do these things.
Nihilism is really just purposefully trying to be worthless. Which is a horrible way to be. Even the lowest person does not truly want to be worthless and they wish that they could be better. I don't believe that there are many actual true nihilists, other than just people trying to show a fictional personality for some strange reason.