Many women lack good social circles these days.
Women are typically more social than men. Women typically have female friends. The typical heterosexual woman has friends in a similar stage of life to where she is. If the woman is single, her social circle is likely to be single. The typical married woman has married woman friends. The typical married woman with children has married woman with children friends.
Alpha males also dont go around pursuing women on the streets and Alpha males especially dont give women a lot of one-to-one time without the woman earning it. The whole cold-approach will put guys into beta category whether they understand it or not, most truly high-value guys like celebs, actors, athletes etc are not cold-approaching or taking women out on 1-2-1 dates rather they just get women from social circles even pop stars and actors pickup women at parties to 'have fun' with.
Some men might have friends but not have friends capable of introducing them to single people in their social networks. This might happen because the man has relocated at some point or has had multiple relocations in his life.
These are men who are either reliant upon approaching strangers, sending DMs on social media, or swipe apps.
The more courageous men (alpha or sigma) are more likely to be approaching strangers. Men who approach strangers in non-bar settings are the most courageous. Approaching strangers in a nightlife venue while drinking alcohol with lowered inhibitions is neither an alpha or beta move alone. Beta males are more likely to approach in-person with alcohol in their systems. Approaching women in non-bar venues when sober is difficult to do, even for men with good lifestyle habits (no porn, no masturbation, regularly exercise).
The difference now as compared to 20-30 years ago is that the typical beta male does less in-person approaching now than his beta equivalents of 20-30 years ago. Beta males of the last 10-20 years have been more reliant upon tech-based date arranging methods.