You don't have to add funds. If you get the wallet and add the address to your nostr profile then I will send you some sats. Participate in discussions and other people will too. The thing that makes it cool is there is no middle man. I can send you something with real world value directly, in increments that are fractions of a penny, and it costs nothing to send. You can then do whatever you want with it. That's worth way more than collecting likes.

It's just a fun thing that makes nostr unique. It's not a scheme to extract money out of people. You don't have to participate if you don't want to, but there's no reason not to. Getting the wallet and adding the address costs you nothing.