If a woman has a social circle, there are only a few men who have features/traits which women find attractive.

So if a woman has a circle of 50 people, out of them only 1 or 2 men maybe attractive enough to spark primal raw desires in her.

On internet, she will see 4ft wide and 6ft+ tall men with ripling abs.

She will be disgusted and unsatisfied with her local options.

She will be forced to expand her diameter of search which is only possible through online dating.

Going to parties and attending events where attractive men come might be expensive for vast majority of women. Many women are afraid and lack confidence to put themselves out there and prefer to talk over phone/chat before meeting the man.