I have had many critters over the years.
We desex the male calves, they stay docile, don't fight, gain weight and turn into
beef in the freezer. We desex a male foal, it turns into a gelding and often spends it's life with a purpose and in return for care, earns keep (pulling loads or chasing
cattle). To protect the hens and make fertile eggs that can be hatched into more
chickens, you keep a rooster--remove the rooster, and the hens still lay, but no chance of hatching chicks--so you have to keep getting
chickens from another source to keep your flock up and productive.
To control populations of dogs and cats, plus keep females from having litters too young and for too long, plus keep the males from fighting and making more litters; we have our purrs and woofs neutered. I have two
yard cats, they were born in my garage; and I had them neutered at 5 months of age so as not to increase the
local feral population (their mother had been a stray kitten I adopted and by the time I guessed she was old enough to neuter, I realized she was about half ways through gestation--she was rehomed with the girls of the litter on a ranch that wanted a population of working cats). I even had two male gerbils neutered a while back (father and son) so as to prevent population explosion. They were paired with ladies but no more babies!
We had a purebred keeshond and seriously considered breeding her, so was getting her the proper care and looked up what it would cost for all the various tests that had to be done (to prove no vision, heart, or hip dysplasia issues) plus what it would cost for breeding, 'well puppy' care, and all. Really staggering and yeah that's why she cost so much... then she went through her first cycle and lost her bleeping mind, seriously. After cycle, she mellowed some and we decided she was NOT a mother, and we wanted her to be OUR doggie, so she went for neuter. She seemed very happy with not going through a cycle again and after the neuter, turned back into her somewhat saucy, bratty, adorable self again.
Heck, I'm neutered. Missing the plumbing since 1993. Couldn't be happier. Children weren't going to be, and we were both good with it, I was having other issues so I had things out. When the keeshond went to vet, I lifted shirt and showed him the belly scars and said, I had it done, I know what she'll feel like. Vet said he never thought of it like that.
Each case is and needs to be individually weighed, but in general, for dogs and cats, we have far too many in shelters, abandoned, feral, and abused. Adopt a pet (rescue a pet-to them, a good loving forever home is like winning the lottery) and be responsible and neuter them.