I worked at The Solder Factory for a decade. During that time I got face-to-face with the effects of annealing on an industrial scale. This wasn't brass, but it was close, and the basic rules were the same either way.
We would cast billets of raw alloy from its components out of a funnel-shaped device with a water jacket around the mouth of the funnel. The cooling was very rapid. The billets, even though they were meant to be soft enough to eventually be coiled as wire were usually brittle when they came out of the process. If you dropped one of these billets, it would shatter like china. After several weeks of aging, they would be pliable enough to extrude.
The extrusion process required that you heat the billet to a temperature of about 800 F and then throw it into the maw of the press. THink of an 80 ton Play Doh Fun Factory set to the Spaghetti setting. A dozen or so wires came out and these would be spooled. After cooling and setting, the allow was again too brittle, and so it would have to be annealed-- heated and quenched before it was drawn out and spooled into the finished product. If something went wrong in the process, the wire might become brittle again, and needed to be annealed all over again.
The reason I write all this, is that once you've seen annealing on that scale, it's easy to see why brass needs to be annealed. Work it too much-- it gets brittle. Heat it and then cool it slowly-- it gets brittle. After I had shot my first batch of brass enough to get neck splits, it was obvious to me what had gone wrong.
