right.
This article is in Portuguese but it has a graph of volume - Brazilians have R$271 Bi of Thether versus R$171 Bi of BTC.
Merchants (specially illegal industrial scale contraband often controled or associated with organized crime) need USD to pay stuff.
They can not accept the risk of BTC price going down temporarily, because their short term debt is in USD
BTC is not the optimal coin for this use case, at least while USD is the currency of international commerce.
Now our commie-bastard government announced a 22% tax on foreign based investiment including crypto. Let the games start.