there is also the problem of encryption, the naive approach puts too much load on the main key that may be stored on a TPM or similar for security

session keys should be established, but at that point you are reinventing TLS and may as well publish unencrypted packets

another problem is overhead: from base64 encoding binary data to having things like WS and 2 reliable transmission stacks

and in the end relays are just a rendezvous point for client/server, and there are already solutions like TURN

for privacy benefits you can use the already actively developed project I2P, and there is no advantage to NWS