As someone who has never really cared one way or the other . . . Why does the sex of your offspring matter to you? What are you missing/unable to do with a daughter that you could do with a son?
I realize it's almost 2019 and as a result we need to pretend boys and girls are identical, but in reality that's generally (but not always) bullshit. I have two daughters. I try to engage the older one (6, younger one 18 mos) in as much stereotypical "guy stuff" as I can, but about 85% of the time she'd rather be off playing with dolls. She has "boy" toys, toy cars, toy tools, etc, but most of the time she naturally gravitates towards the girly stuff when given the choice. Even the younger one has a favorite baby doll she clutches and walks around with and pretends to feed etc, and has no interest at all in playing Hot Wheels with me.
So yeah, is it possible that a boy would also have those exact same interests? Sure, it's *possible*. But it's less likely. We've gone out of our way to encourage our daughters to ignore gender labels in sports, activities, etc, but at the end of the day the things she loves the most are baby dolls, barbies, and cheerleading, all traditional girl stuff. Just the facts.
All that being said, I thought I wanted one or more sons, but to be honest, I love my girls. Frankly, as a man, it's a lot of pressure to raise a young man, especially as somewhat of a more traditional guy. The things I would want to teach him are not necessarily in line with today's expectations, and that would be tough for me to reconcile with him (e.g., I was taught to stand up to a bully physically if necessary, that is not a recipe for success in today's environment). For a dad raising daughters, it's a different kind of stress, the emphasis is on being there for her, less so on teaching her "how to be a woman" because that's mom stuff. Also, young boys are insanely hyperactive (I have young nephews and friends' kids) and I don't know that I have the patience to deal with that. OTOH, I will have the teenage girl years, so...
There's also a special father-daughter (and I guess mother-son?) bond that I get to have with both my girls, that my wife is often jealous of (my oldest and I are closer than she is with my wife).