Zelle isn't run by the banks, it's operated by Early Warning and it's a scam service designed to harvest everyone's bank transaction history for intelligence gathering and fraud detection services
> Zelle is owned by Early Warning Services, a financial tech firm and consumer reporting agency that is co-owned by seven of the largest U.S. banks: Bank of America, Capital One, Chase, PNC, Truist, U.S. Bank and Wells Fargo,
Once you are part of the banking system, everything is tracked anyway
https://www.earlywarning.com/