We are talking about tax evasion. That's exactly what this $600 threshold is targeting.
You want to keep moving the goalposts?
All income must be reported and is taxable, that has over a century of case law to protect it. Requiring third party financial processors to disclose their data also has well-established precedent. If banks do not voluntarily disclose, then they risk liability for criminal financial activities processed through them (Bank Secrecy Act of 1970).
I repeat - the Constitution does not provide a recognized individual right to financial privacy from the IRS, and even if you did, that does not shield you from parties on the other side of your transactions from being forced to disclose to the IRS. What protections on your banking data you do enjoy are established by the Right to Financial Privacy Act of 1978, a law passed by Congress, and thus amendable by subsequent Congressional legislation.
The wikipedia summary about RFPA even cites the 1976 Supreme Court decision that established financial records are the property of the financial institution, not you, therefore not covered by the 4th Amendment, and thus upholding the 1970 Bank Secrecy Act provisions around forcing banks to disclose. That's why the RFPA was even introduced. Feel free to read further:
https://en.wikipedia.org/wiki/...