I grew up with a ton of different pets. Dogs, cats, reptiles, rodents...
Dogs are cool but once you get used to only having to dust your place it's hard to go back to all the balls off fur and messes. They are good for therapy and security.
As an adult, I've thought about getting a dog again but I'd need a pretty specific set up: House with a closed backyard, hardwood and tile floors and mostly leather furniture, Roomba vacuum etc.