It took a great deal of hard work and skill, and no small amount of luck, to keep all of Portuguese South America in one piece. And because of Bland United Brazil, none of that gets appreciated.
There's no reason that Brazil should exist. It's the single largest state in South America, and its population is overwhelmingly concentrated on the southeast shoreline. Nothing except language necessarily unites the north with the south, and language wasn't enough to hold together the Spanish viceroyalties. And yet Brazil is almost always there, and almost always about as big as IOTL. There usually aren't two of them. Or a mess of impotent, poverty-stricken Lusophone statelets where Brazil should be.
Incidentally, Bland United Brazil overlooks the reason that United Brazil exists today: it wasn't bland. It was South America's only monarchy, and the only stable government on the continent for the first 60 years (after which it was overthrown by a military coup, turning Brazil into South America's only Lusophone caudillo state; it spent the next century recovering.)