Venmo processed about $20 billion in 2016. ACH: $45 trillion.

And Venmo would not exist without ACH.

Nonetheless Venmo exists for a reason, User need. It would also be more comparable if one were to be able to buy Government bonds as a corporation using Venmo to make your comparison aapt, alas you can't do that.

If one were to compare sub $50 payments on retail banking ACH vs Venmo you would have some valuable information indeed.