I was riding last week after work in modest traffic. A car pulled out of a garage from behind a line of cars backed up at a light. I wasn't going particularly fast but was caught unawares and hit the brakes (road disc). I abruptly pulled up short.

Sure any brakes can do the job. But disc brakes are available to stop without hesitation under any conditions. There's no split second of "wiping water off the rims" or "getting them to bite", they just work: reliably, progressively, and economically

My rides take place in any conditions and I look forward to the day when all my bikes have the option to be set up with discs.