Why do babies cause relationships/marriages to fall apart? Is it worth it?

You see it time and time again, how people break up after having their first child. In marriage, people will write about being together happily for a decade, then suddenly their marriage starts falling apart after they have their first child together. I think that if more couples knew how much a baby could negatively affect their relationship with their partner, they would decide that a baby isn't worth the strain on their relationship. I've been googling about how babies ruin marriages, and I keep seeing people complain about how they barely argued with their partner before the baby, and now how they can't stop arguing. I've also been looking up a lot of stuff about newborns, and new babies sound like hell. People are complaining about sleep deprivation and the negative toll a new baby takes on their mental health. They literally call it "the newborn trenches" and say it is the hardest, most stressful, draining thing they've ever done and it damages their mental health and how they go days without sleeping because of the new baby. New babies are HARD, and it's usually with a new baby that even the best relationships start to unravel. After doing so much research, reading other people's experiences I'm to the point where I don't think a baby is worth it. Having a baby isn't worth potentially losing the most important relationship I currently have, and that's the relationship with my husband. I don't think my relationship can handle the stress of a baby, and why test it? Babies more often than not, they ruin relationships.