It only seems that way because Scully works alone. However, he does pause at times. He’s famous for not talking over a cheering crowd. And when he does talk, he does so in an unrushed way.
Now, with two or more in the booth, someone is always talking, and speed talking at that. There is no dead air. (Sponsors fear dead air. They think dead air will cause viewers to change channels.)
Yes, I am once again in the minority. I do have a mute button and use it often. Also I can fast forward as I want.
Compare that to Tom Hamilton of the Cleveland Indians. If an Indian makes an out, Tom gets all gloomy and runs him down. But if it's a hit, Tom starts shouting and exulting. Talk about manic depressive.
Although I'll take that over the goofy Padres announcers.