The significance of complications being the best way to launch apps is why swiping between watch faces is so valuable. It allows users to literally switch their context on the Apple Watch. One day this could presumably happen automatically, but at least it only takes one swipe to switch from your primary daily watch face to one with the type of information you want to have at a glance in another context.
I love using the Stopwatch and Timer apps while I'm cooking or brewing coffee, but I don't want their complications visible during the rest of the day. The ability to swipe left and bring up an entire watch face devoted to them and any other complications relevant to cooking is a game changer for me.
Prescient realization by Stoll about the implications of the new Apple Watch swipe-to-change-face feature. While Apple emphasized the Dock during the keynote as the new best way to switch between apps, maybe that crown will really go to Complications on various watch faces.