The choice to have kids or go child-free is completely personal, and shouldn't dictate how you choose your friends or treat people. People have wildly different values and visions for their lives, not to mention varying health issues and relationship trajectories, so it's truly a false equivalence to compare two people's life choices.
That being said, there are still plenty of people who center their identity around having kids and obsessively pressure others to join the ranks of parenthood. Likewise, there are some child-free people so deeply opposed to having kids that they become antagonistic and smug.
AITA for finally poking back at my child free sister-in-law?
My wife's sister Abby is "child-free." Neither my wife nor I could care less about whether Abby decides to have children, but over the years we have tolerated quite a bit of performative child-hating from her. Calling children "crotch fruit," talking about how dumb people are for becoming parents, and so on.