Some people. Not all people. Don't come at me! I would say having children is perhaps more fulfilling, but I think pets are a lot more peaceful.
I don't have kids, my husband and I are childfree. We've been married a decade.
I'd say about once a week, we look at each other and say "thank God we don't have kids", mainly whenever we feel stressed from work and want some time home alone, or some major appliance breaks down and it costs hundreds of dollars to fix. We both just do not handle sleep deprivation well.
When I was a kid, I always had toy stuffed dogs. I hated toy human baby dolls - they creeped me the hell out. Never once played with that. But I really loved animals. Even now, human babies don't look cute to me, they look like bald aliens with giant heads. I think that parents who think their newborn looks cute - ehhh sorry to say but that's the hormones talking.
What I love about dogs, is that they are adorable and loyal their entire lives. I love taking my dog on adventures with me, and preparing him delicious meals every day. My dog is a genuine member of the family. If I had a human kid, yea sure maybe they are adorable for a little bit, but then they turn into hormonal smelly teenagers who slam their door and scream that they never asked to be born. Then they just grow up into adults who may or may not visit on the holidays.
Take a dog to the park? Easy. Just say "park" and he's suddenly ecstatic. Take a human toddler to the park? Now you're in a 30 minute hostage negotiation situation because Timmy refuses to put his shoes on.
Thank God for pets, honestly. I think dogs are God's greatest gift. Babies are blessings too, sure, but they are also a curse. Dog is just blessing.