It’s a biological drive. Animals have evolved to desire multiple partners because it increases the chance of genetically healthy offspring.

Many people are completely controlled by their reptilian brain and their instinctual desires.

Humans are susceptible to programming. We learn how to behave from our environment. The culture uses hyper sexuality to attract attention of the animal brain. This has caused it a feedback loop of extreme hyper sexuality. Good luck navigating this world if you’ve avoided it and are trying to find a partner that does the same.