Why would anyone ever buy moons when they’re free from upvotes? If nobody wants to buy them, how can we ever sell our moons?

I’m trying to understand the moon token economy. I don’t get how it can possibly have actual monetary value when you can get them for free for upvotes. Is there anything you can do with moons besides sell them for another currency? I assume if we’re selling our moons for another currency somebody else is buying them, but I don’t get why someone would buy it.

Thanks in advance