Can’t quantify the feeling of having kids until you have one, but it’s very easy to articulate the perceived drawbacks of said unknown. They bring a life buff like nothing else, speaking a someone who regularly chases altered states of consciousness.
They provide a large opportunity for some enormous maturation, removal of bitterness/edgelord-iness and to not be so self-centred.
Your description of kids sounds like me beforehand. Have 2 happy accidents now.
Lie-ins are still possible if you are actually in a decent relationship by the way. To anybody reading, don’t have kids if you are in a bad one. No kid deserves to grow up around that.