Depends what you do and where you live. We used Pozidriv in England in the motor trade back in the 70s,(do they still?) and still use them in NZ today in the building trade, but square drive is gradually taking over for builders. In the airlines they use a tri-wing, like Phillips but only three blades. Chinese and some Japanese stuff seems to use Phillips. The main advantage of Pozidriv is that you don't shatter bits quite so easily when using a power driver, but they still strip out like Phillips do. We are also getting some heads that take everything, both stardrives and slotted. All badly.
There are also lots of other security bits to stop the proles messing with things that they don't understand.

Gnu, Pozi does hold the screw, but only until the bit starts to wear a little.
Frogprince, hex-drives used to be, and by specialists still are, called Allen-head. They are often in high-tensile applications.