How do you know I don't understand math? And if a high schooler could figure this out, then Leibnitz own discussion or contribution to this topic is then meaningless?

The main point is that the finding in the article has cultural significance, rather than purely in terms of mathematics. I think you either don't understand that or are not willing to see that. The article is not trying to elevate a Polynesian people's contribution to mathematics. There is little mathematical significance there as these people from 600 years did not celebrate or promote their number system. Rather, the article explores how mathematical knowledge arises and how it was used. Could there an underlying commonality in the way humans learn and organize knowledge? That's an interesting question to ask and is not diminished - but is in fact supported - by the fact that the same knowledge gets rediscovered in multiple isolated instances.