The most over roasted slop around, sure. There's a reason why that place serves pure diabetes, their black coffee is kinda gross.

maybe the coffee is gross so that it can pair with the diabetes. That much sugar needs a very strong flavor to offset it.

Or Starbucks just uses the absolute cheapest beans on the market and then burns them for that truly consistent char flavor, which they then have to turn into diabetes to make palatable.

Either way, it's just not good.