While its true there are outliers like fundamentalists who go to extremes and progressives who deny many rules, there are four major schools in (Sunni) Islamic law that the majority of people follow and they all take at the very least the ruling that the covering for women is everything except her face, hands and feet - when among men who she legally can marry (“mahram”).
The root of the thing is that Islamic teachings require practitioners to dress modestly.
Interpretations of this range from “cover your sex bits” to “don’t show an inch of skin to anybody except your husband”.
While its true there are outliers like fundamentalists who go to extremes and progressives who deny many rules, there are four major schools in (Sunni) Islamic law that the majority of people follow and they all take at the very least the ruling that the covering for women is everything except her face, hands and feet - when among men who she legally can marry (“mahram”).