Retaining is more important than acquiring
Whether your goals are monogamy or sexual abundance, being able to keep a girl is much more important than being able to get new girls. Nothing is more frustrating than spending a fantastic night with a great girl, only to get blocked in the morning, nothing feels empty and meaningless like a succession of one night stands leading to nothing. Getting a new girl every week, let alone every day, is almost impossible in the long run unless you make it a full time job. But if you smash once a month, which is realistic with efficient use of dating apps, and keep every girl on average six months, you'll have a permanent rotation of six girls to pick from (or more realically three or four taking into account their periods and shifting moods). Not all men, of course, have the necessarily skills or are interested in managing that level of complexity. You can eventually choose one as a permanent monogamous partner should you desire to do so.
The qualities needed to keep a girl are slightly different from thoses needed to get one. The men who keep women around longer than a night or two tend to deliver consistent value in a few domains: strong sexual polarity and skill, emotional steadiness (not volatility or excessive validation-seeking), interesting or high-status lifestyle, and the ability to create comfort without collapsing into pure friend-zone energy. Following up on commitments, and being organizationally predictable, are also important - impulsiveness and unpredictability, which may be attractive at first, can quickly become tiring. Acquisition openers and day game lines matter less once the first night has happened. The gap between “she liked the night” and “she wants to see him again and again” is mostly post-sex behavior, texting calibration, and whether the overall experience feels additive to her life. For pure monogamy goals the same retention skills still dominate, just applied to one person with higher investment and clearer exclusivity.