PIX is only for locals as you need to register with a CPF (Brazil ID number which is hard and tedious to get as a tourist). I ran into many scenarios where the only option was to pay with PIX and the staff aren't used to tourists and look at you funny when you explain you can't use PIX.
Also beyond PIX, if you try to book buses, planes, or take out a gym membership, while you're within the country, 99% of the time it's shockingly impossible to pay without a CPF, even by credit and debit card. I've even seen this for paying the laundry machine.
I'm sure the PIX system is great for Brazilians, and it was helpful having a local friend to make payments on my behalf, but Brazil really lives in a bubble where it seems a side-effect of their system is making things actively very hard for visitors to operate within the country.