Agreed...
Certainly many people weren't meant to have kids, but have interest in what results in kids, so having kids ends up being a side effect. My mom was not meant to have children, but here I am. Guess how that happened. I think she's still trying to figure out how it happened 33 years later.
I'd be curious if you would have said the same thing 15 years ago, when your kids were around the same age mine are now (5 and twin 3 year old girls). I love them, they're at great ages. We have a ton of fun together. The girls, being twins, are not only cute, sweet, and funny, but the twin bond is incredible to watch. My son can drive the tractor (on my lap, of course) and "helps" me turn wrenches. Sounds great, right? And it is, it absolutely is.
When our son was born he wouldn't sleep more than 45 minutes at a time through the night and the crying was incredible. Massive sleep deprivation for both my wife and me, but mostly my wife for the every 45 minute nursing (sleeping 2 hours at a time? That would've been great! He didn't do that until he was 2). Would not sleep for me, period, just scream. If we were lucky my wife could transfer him to me after falling asleep, but that usually didn't work.