>>149278891Not exactly. Flamengo were already a somewhat popular club in Rio in the early days, and then they got a really nice boost because the biggest Brazilian media conglomerate (also based in Rio) shilled them in the national newspapers and the radio. Since clubs from Rio and São Paulo have been the best from immemorial times, it became common for people from other states to support them even if as a second club. The result was that they ended up with lots of fans over the entire country.
More recently, they finally capitalised on it and started drawing massive cash from the size of their fanbase, which led to Flamengo becoming dominant in the league. But they became strong because they had fans, not the opposite.
That being said, I do get the feeling they have a lot more casuals than other people. Not like people who started supporting City in 2021 or the kind that hops between Real and Bayern every season, but the dumb girl type that uploads Insta stories from the stands and can't name the starting XI.