It's a bit more nuanced than that. First and second cousin marriages in Pakistan account for 56% of all marriages. 8% of those are second-cousins, 28% are cousins on the dad's side, and 20% are cousins on the mom's side.

But each ethnic and religious group of Pakistan has different customs, and subgroups of those have varying customs, so there are areas where cousin marriage is taboo, and there are areas where almost everybody is married to their cousin. Depending on your ethnic group, generally you are only allowed to marry cousins on one side of the family, but marrying cousins from the other side of the family is taboo.

For example, cousin marriage is close to nonexistant among many non-Punjabi Muhajirs, due to cousin marriage being historically considered incest in North India. While the cousin marriage rate is higher among Punjabis and Pashtuns.