You don't need a permanent residence, but to use PIX you have to get an ID called CPF. This is your IRS number, as you said, tax number. It's easy to get but it takes time, you can have one as national from different country.
OK so it's firmly in the "not reasonable" territory for tourists. Just pay cash or credit card. Tourists aren't going to wait a while for a Brazilian tax id then use a Brazilian bank account before their trip. Just to select Pix as your payment method instead of card you already have in the Uber app.
This isnt a take down of Pix. Sounds excellent and should be replicated in other countries. Lets just not pretend its a viable solution for tourists.
