Incandescent bulbs don't visibly immediately transition to a harsh on/off state like LEDs do when operating at the same frequency.
Incandescent bulbs are still burning and emitting light during that brief period of "off" time, and CRTs have a similar "effect" that allow the interlaced lines to display smoothly on the screen AFAIK, although I will admit CRT flicker is much more noticeable
TIL, thanks for the info!