No, they are trivial to block using techniques like deep package inspection.

In addition to that, they aren’t truly decentralized (no decentralized network really is), both rely on relay/bootstrap servers to start up the connection. So, if you block the public relay/bootstrap servers, you effectively block access to the network.

Tailscale, netbird also can traverse NAT.

Iroh (the actually pretty interesting software which the vibecoded rayfish is based on) and Yggdrassil do have their uses, but evading blocks isn’t one of them.