[tornato7]

Good question:

Transaction cost: about $0.75 on Ethereum or $0.01 on Polygon at the moment - no size limits. Zelle is free up to ~$1,000 per day.

Settlement: 12 Seconds on Ethereum or 2 Seconds on Polygon, "instant" on Zelle. However many transfers on Zelle use ACH under the hood, so it may take 3-5 days to settle with your bank. If the recipient isn't enrolled in Zelle it may take 14 days for them to register to receive funds.

I'll note that I regularly move USD around as part of my job and have always found USDC to be a superior experience than bank transfers - especially because I can use smart contracts and custody tooling to set custom transaction policies on required approvers, whitelisted recipients, etc.