I'm not a business, so I don't know if Venmo charges businesses 3% if they receive a payment, but in every Venmo transaction I've made, either sending or receiving, the money sent was the money received. I have never been dinged 3% for any Venmo money sent to me. My landscaper accepts Venmo and I've paid him that way several times. I doubt he'd accept it if he didn't get paid what I was supposed to pay. If I owe him $100, why would he accept a Venmo payment from me for $97? Maybe it's because I've ever had to use my credit card for payments?
As for PayPal, I have always had payments get reduced by their fees. It's why I increase my asking price a bit for stuff I sell on-line. I know I'm going to get dinged, so I build that into my asking price. I don't use "Friends and family" for CD/LP sales on-line because you lose payment protection when you go that route & I'm pretty sure that in cases where you use your credit card for a "Friends and Family" payment, they charge you the 3% too.