0%, no charge? How do you avoid the risk of being used in a swindle, where the party that paid a fraudulent invoice then tries to recover the payment from you?
There is a possibility that some swindled payer might see the matter differently, though, and sue you and the swindler, together, blah blah "jointly and severally" blah. I assume Venmo spends real money on fending such lawsuits.
Same as with Venmo, if you paid a fraudulent request, that'd be on you. There's nothing to recover because the transfer was successful.