I can understand how and why you'd feel this way when you compare hydraulic discs vs rim brakes on a carbon surface in wet weather.

I'd like to see GCN or someone else compare rim brakes on an alloy surface vs hydraulics in various ride conditions. GCN has already found that in dry conditions, even rim brakes on a poor braking surface such as carbon stops just as well as hydraulics.

My bet is that a top end set of rim brakes such as dura ace 7900 would brake almost nearly as well as hydraulics in wet conditions. Stopping from 40km/hr I would estimate that the difference in stopping distance would be 5 feet or less (approx 1.5 meters). It's likely that rim brakes would have a slightly shorter stopping distance in dry conditions as well.

Hydraulics give you a bit better performance in wet and very wet conditions on rough roads. In other words, they are great for mountain biking and cyclocross, or for riders who ride frequently in wet weather. Most people ride in dry conditions negating any possible advantages of discs.