People who have a lot of partners have more people to compare their current partner to.
And because their partner may have negative traits from partners they fell out with, and start to exhibit traits that other partners they weren't compatible with, they're more likely to end the relationship because comparison is the thief of joy.
Marriage is an arrangement that benefits women. When they marry they gain access to their partner's resources and in the event of a divorce, they leave with some of those assets. It doesn't even matter if she had a "hoe phase" or whatever. Passport bros are living proof that there is literally no such thing as a guaranteed outcome with many of them getting finessed out of their bread less than 5 years into the marriage. There are billions of dollars being made every day by suckering men and women into thinking that there's a foolproof, 100% guarantee of long term relationship satisfaction there.
America is the land of opportunity if you're bold and unethical enough. There's a sucker born every minute. This is how men like Andrew Tate and magazines like cosmopolitan can stay rich.