Payment systems take huge fees. It is always good if they get back to the country and not elsewhere. Digital paying is something fundamental. Like electricity.
Brazilian Pix is free though, at least for the time being. IMO the biggest thing is not the money behind it, but the ability to track individual payments. Even that, I prefer the government to have that information, than some shady owner of a private company
PIX are free for persons.
Companies may* pay for pix services. My bank (that is not a good bank) charges a fixed amount of 4 BRL (aprox 1 USD) per transaction (to send PIX. not to receive)
PIX in "maquininhas" may cost ~1% to the seller.
Fast, free, and frictionless payments allow the economy to run better. That's better for the government and the people. Only corporations like Visa and Mastercard lose.
That is the monopoly cost. UPI is free for both payee and payer. Whatever it costs banks to operate it is covered by reduced cost of dealing with cash/consumer.
To give some reference, using stripe you pay 2-3% for credit card payments and PayPal charges you ~5% of the transaction amount. Apple store and Steam take 30%. So honestly 1% sounds like a great deal.
I think comparing Steam and to some extend Apple with payment methods, they are stores and it cost money to store apps and games and for this one I'm not 100% sure, but I read a while ago that they also pay taxes for you in the country you sell, while pure payment processing services are just a proxy to move money from one account to another. You could argue that 30% is high for that, but we aren't discussing it here.