Great article. I think I can add a few things (I'm brazilian, btw).
  • Other forms of money transfer (TED and DOC) charge a small fee, and Pix doesn't. This is one of the main reasons it caught on so fast;
  • Many bitcoin/crypto exchanges that operate here offer deposit and withdraw via Pix (Binance, for example);
  • There are even Telegram bots that allow you to buy and sell bitcoin using using a combination of Pix and Lightning Network;
  • About the UX: Pix allows you to charge some one using a QR code invoice. Let's say I owe you 100 bucks. You then send me the QR code for said 100 bucks and all I have to do is scan it or copy it into my payment app. HOWEVER, I have yet to come across anyone how knows this, and I have a small business, so I have to pay a lot of people using Pix. None of them have ever sent me the QR code thing. They always expect me to initiate the transaction. Weird.