Zelle payment transfers are painless, instantaneous, and free. I can do it from my bank's app or online banking page. Punch in the person's phone number or email, enter the amount, done. They don't even have to accept the payment. And nobody has to describe what the transaction was for; it's highly private, beyond who the money came from / went to and the amount.
The caveat is that the money transfer cannot be undone for almost any reason. There's zero customer/purchase protection. The Consumer Financial Protection Bureau, however, has instructed banks that part of the Electronic Transfer Act requires banks to refund people if the transfer was a result of them being tricked into giving up their account details (it's not clear if this means the money would be yoinked from the recipient.)
I kind of would like the option to enable some sort of confirmation and/or 2FA for a Zelle payment (mainly this means disabling it via the website; my phone provides bio 2FA), and confirmations for receiving a payment. Those are my only complaints with the system.
But that means it can be trusted by people who want to know, for certain, that they've been paid "for real." It's instantly settled, unlike damn near every other form of money transfer system where even if the money seems to be in your account, there's still a days or WEEKS long delay until the transaction can't be yoinked back.
This makes it great for if you're selling a car and about to sign & hand over the title to the other person, for example.