You're far too optimistic. The current administration is trying to work itself out of a major economic crisis and there's nothing they would like more than to tax the crap out of every single Pix transaction.
This is a country with obscenely high interest rates, currently at over 14% per year. It's just ridiculous. And inflation is still hovering between 4% to 5% per year, just under pandemic levels. The solution is for the government to stop spending money. They don't want to do that, they want to increase taxes instead. As a result, we're at record breaking taxation levels, last year Brazil achieved its highest tax revenue since 1995.
The current administration spent the last two years crying about the central bank's high interest rates. I can't even fathom what'd happen to this country if they got what they wanted. Mercifully, central bank has some degree of autonomy from their stupidity. After a couple years they get to appoint the head of the central bank. It turned out even their own guy wasn't stupid enough to lower the rates.
I think the only reason they haven't taxed Pix yet is the fact Pix is too popular already. I have no doubt they're still gonna manage to increase revenue by cross referencing Pix data for tax purposes.
Watching the Indian and Brazillian governements solve this problem by by building the payment networks themselves and removing the profit incentive has felt vindicating.