Can you elaborate on how the risk of ironbank and hornpub colluding by de-anonymizing you via rainbow tables or IP forensics is substantially greater than Chase and PornHub using - Google Marketing?
It isn't, but due to bureaucracy, when designing a solution, it's that solution that has to be "secure" without really considering that the current outside situation is already insecure..
Anyway I'm not advocating for this solution, just addressing the question directly.
The ZKP approach aims to prevent this attack method.