most places i visited (remote rural places like districts of > 300 people up to big cities) have a rechargeable card system where you can buy at any terminal
some buses in the surburbs of big cities only accept cards nowadays and you can recharge it online in 3 minutes (ofc if you are a citizen... brazilian goverment websites is a huge UX pile of shit; police, mail etc.)
These systems are all built to help the bus owners, not the passengers.
Usually you have to go register for a card somewhere. It's just not practical, especially if you're just visiting. I've never seen a place where you could buy a card at a newsstand for a week or something like that.
if you are visiting a city and you are exclusively using the bus, in 2 or 3 travels the card pays itself for not dealing with coins and physical money... you can literally buy them in 5 minutes, no need to have a CPF exposed or whatever [they are called TOURIST CARDS for a reason]
around Paraty -> Angra dos Reis region you can literally visit/stop in more than 25 beach spots with the buses who circulate that area
and it's really nice that it helps the bus drivers. it even saves some time on embarking, which can add up in longer routes.
godspeed on a single card (state agnostic) for the entire public transportation system (metro, bus, trains) in Brazil
some buses in the surburbs of big cities only accept cards nowadays and you can recharge it online in 3 minutes (ofc if you are a citizen... brazilian goverment websites is a huge UX pile of shit; police, mail etc.)