bitcoin

Since only economic nodes matter, doesn't this sound a little bit like POS?

BTC_Commons

With respect to what we call **nodes**, we do treat them the same. The wiki page you linked tries to group in **light clients** , which are programs that rely on a 3rd party for blockchain-related information, with nodes. 

If everyone is running programs that query information from 3rd parties, regardless if it's from a purported 'full node' or a website, the client *can* be fooled. Thus I'd rather say Bitcoin is not susceptible to Sybil attacks, but users of applications that pull from bad sources *are*.

And this excerpt from the linked bitbox article is just wrong:
> While the Lightning Network gave a boost to the number of Bitcoin full nodes, many are not used to verify economic transactions and secure the Bitcoin network

**Nodes**, especially what we consider **full nodes**, *do* verify all transactions.