I always assumed the goal wasn't to minimize the time you spend in a UI but to find the maximum amount of time users will tolerate using a UI. At least for UIs

I always assumed the goal wasn't to minimize the time you spend in a UI but to find the maximum amount of time users will tolerate using a UI. At least for UIs that feature ads that is. The longer you're on the ad-spewing platform the more ads you're shown etc etc. Partly explains why Google search results are unnecessarily bad these days.