Better for your kids and better for your wallet to keep a wife and only that 1 stable partner.

Better for you too if you are capable of being more than a walking boner. Describing men as just a sex drive leaves a lot out of the picture. While what he describes is common, lots of animals do pair bond for life and the male remains loyal to that 1 partner.

Pair bonding is more common in species with fewer kids. The fewer kids females are willing or able to have the more evolution will favor males who stick around and invest in their children.

I kinda suspect humans are in the process of evolving away from spray and pray towards pair bonds but it hasn't fully finished yet. How do fatherless kids fare? How long does it take humans to reach adulthood compared to other species?

Being a philandering young man meets your novelty desires but ignores everything else about you. Easier to drive up novelty in a marriage than to get emotional connection in a 1 night stand.