Since you mentioned Zcash and Namecoin, do you have an opinion on ENS, Aztec Protocol, and zkSync? They are trying to solve the similar problems that projects you mentioned do, and somewhat fall into Web3 umbrella.
I haven't looked into zkSync or Aztec just yet, but I'm assuming those are dealing with the same problems as Zcash, but on the Ethereum chain? If this means you can just throw in some generic ERC-20 token and get a zero-knowledge version of it (like what z-address is to t-addresses in Zcash), that's pretty cool.
[1]: https://www.reddit.com/r/handshake/comments/lo894k/differenc...