Your rotating beacon (and navigation lights at night) won’t bother anybody during taxi and should already be on before takeoff, but anti-collision lights are extremely bright and can blind other pilots. That’s why you shouldn’t turn on the landing light or strobe until taking the active. (Seeing these lights come on is also a subtle, nonverbal cue to the tower that an airplane is about to depart.) The exception is for airplanes, like Cirrus models, that need the strobes on for ground ops because they lack a beacon. And in some airplanes, like those equipped with Garmin's G1000 cockpit, the "camera" (i.e. transponder) goes to alt mode automatically.