In fact, even with the apps it's sorta gimmicky. Unless you use it for health purposes (e.g. heart monitoring), a smartwatch is not of the "my life change" category. At best the "I could do the same shit with my mobile phone, now I also have another device for them that I can do them in a worse screen/input method".
I suspect it's something really subtle along these lines: Beautiful women can often get by being useless, so women in general acrew certain trappings of uselessness so as to associate themselves with beauty.
It's sort of like men and commuter pickup trucks (trucks are associated with hard-working men, so men buy trucks and drive them around town, even though they have no hard work to do).
And aesthetically, a pocket stuffed with things, especially in more form fitting clothing, doesn't look good.
Actually, adding pockets to women's apparel might be a decent side-gig business....