Cold brew vs. Japanese iced coffee
Cold brew is not the only way to make iced coffee. The other method I use is the Japanese one: brew pour-over with hot water directly onto ice, so it cools instantly.
They taste surprisingly different. Hot extraction pulls out the bright, acidic, fruity side of the coffee. Cold brew is rounder and sweeter, with less acidity and more chocolate and nut flavours.
In practice I use Japanese iced coffee for light roasts, especially fruity Ethiopian coffees. Brewing those cold tends to make them taste muted. For medium and darker roasts, cold brew wins for me.
The practical side
Japanese iced coffee takes five minutes but has to be made fresh. Cold brew takes a day but sits in the fridge ready to pour. On busy weeks that difference decides it, whatever the beans are.