My guess was the $20K threshold, especially when combined with the number of transactions, was intended to catch the bigger fish and serial tax frauds, that maybe use Venmo to pay a bunch of vendors/subcontractors with no intention of ever filing a 1099. Like a contractor that pays his subs that way all year, but never pays them over the $10K bank reporting requirements in one payment, and never files any 1099's. Or the hairdresser, baby sitter, etc. that makes plenty of money, but is paid by a bunch of individuals (rather than by a business required to file 1099's), and never reports the income. Both of those examples could easily hit the $20K and transaction threshold, and would be worth the "squeeze" to go after.

Yes, there's a lot of gap between $600 and $20K, but that $20K is total for the year. How much squeeze are we going to put into going after folks getting less than $20K? Not like they'll be paying taxes on that. (yes, I realize that's only one type of payment, and that it could be above some even sizable taxable income)