what exactly is an "africanized" bee?
Long story short, there was a university in Brazil (or thereabouts) that as doing experiments with breeding for the “best honeybee”. An intern/assistant/student/etc saw these little things blocking the entrances to a bunch of hives one day and decided that they didn’t belong there and removed them. Turns out that those were queen excluders (to keep the queens inside) and this let out a bunch of these experimental queens.
And that’s the story of how africanized honey bees happened. It was an accident.
But they’re basically just normal old honey bees that were bred to be very aggressive (way past defensive) and super productive. From what I can tell, they only achieved one of those goals.