Earlier quoted context omitted.
9 BRL is what? 2 USD? Compare with https://answers.usbank.com/answers/s/article/How-much-does-a... (spoiler alert: 10x more - for both senders and receivers) Whatsapp transfers would be ~ 5% of the cost which would make it more expensive for anything over 200BRL Meanwhile inside the SEPA Area (EU), National and International payments have the same cost (which is usually 0)
In the US I pay $0 for transfers under like $2500 using various free services like Venmo or Cash App.
Do business accept Venmo (I know some do, though it seems Venmo is backed by a pre-paid card)? Can you pay your rent with it, for example? Tuition? Buy a car with it?
The payment methods I mentioned don't require people to install an app or enter an agreement, you have a bank account they're available to you. Sure, there's some typing of numbers (but that's pretty much a copy-paste today). Not to mention the privacy issues with Venmo.