I want to get a dog but I have to work, how does everyone on broadway market do it ?

What’s the reason given for waiting till they’ve finished growing? I’ve also heard that but not heard why

Just googled it and this is the clearest concise summary I can find:

Having your dog spayed or neutered early will not stunt your puppy’s growth, but it might affect the joints of large breed dogs. Studies show that early spay/neuter does affect the growth plate, delaying its closure and causing dogs to grow taller than they should have. This can predispose the dog to later joint problems.