A more important factor in the app-switching use-case, imo, is that Spotlight or Alfred require just static unchanging input, so you can bash it out without second thought, and usually without looking at the displayed result (after learning the necessary text to trigger the app selection). When cmd-tabbing, you have to look at which app is under the highlight ‘cursor’ and where is the one you want, then position the cursor on the desired app—this all keeps visual recognition engaged and requires conscious choice at many steps.

This is also the reason why both mouse-clicking and touch-tapping are slow compared to keyboard typing: you likewise need to look at what is where on the screen, then aim with the mouse or the thumb, instead of just jerking the fingers to keys that are in muscle memory.