Personally, I feel pets are always a burden financially, emotionally, and environmentally.
I am totally in support of native species who got destroyed by pets turned feral. If there is no demand there will be no supply. People who breed these dogs or cats do breed specifically because there is a demand. Humans already go through a lot of trauma and personal losses, why add a few more (pets) to your life which is totally avoidable. Is companionship a reason? Or do humans want to feel special? Domestication is fairly recent in our evolutionary past. No other animal will take care of another species in the wild(If they do, we will consider as a wonder). Then why do humans do it? Is pets are one of the side effects of having an analytical and creative brain like the creation of religion or have people fell for marketing fairly recently like diamonds and Halloween or Fathers, Mothers, Valentines days, etc.
Can you tell what is the reason why you have pets because it is beyond my sense why people have pets?
Because they like the companionship.