Atleast by having a daughter you can guarantee your bloodline. Plus its a fact that daughters are more biologically inclined to love and respect their fathers. Those whores you see on the internet all suffer from daddy issues aka absent father. A daughter with a present father usually turns out ok.
I say its more cucked because biologically mothers are closest to their sons. Now imagine this. You and your wife are older and she thinks you can't satisfy her anymore, then she views pretty much a younger healthier version of you in their son. Now imagine being cucked by your own son, that shit has to be insanely brutal. Atleast wiith your daughter you can get some action, but with your son you cant plus you risk being cucked. Daughters in their younger years always prefer being around their dads. Which is why i say daughter>son. Plus daughters are usually more agreeable with their fathers unlike sons who want to bash heads to show who is the alpha in the household.