Flashlights have many uses, they can be used as work tools or as an EDC companion.
We're always looking for the "Perfect Interface", with maximum performance while maintaining usability.
A basic on-off switch is simple and fulfills many users' needs, but performance is lacking.
Modern flashlights are engineered with tons of features, multiple switches and modes, but at the cost of complexity and usability.
While the features enhance the function of the light, learning and remembering how to use it can be daunting: we don't want the people to need instruction booklets to use a light!