I’m sure the full service tourist hotels and resorts accept US & Canadian dollars, Euros and Yen. When I was there we exchanged dollars for Cuban Unified Currency at 1:1 rate. I traded us currency for pesos with the images of Che but tourists all spend CuC.
This is one of the reasons Havana is safe af and San Juan is high crime zone
safe but tolerates 0 dissent or unsafe and protests in the highway chased the governor off the island (and it’s still high crime and fucked)