Many also pick up pets because of child pressure or simply fads. 101 Dalmatians was a shit show because of the number which ended up abandoned as people didn't realize that a large dog was an impact.
Rescue groups are full of dogs that are abandoned because they are too old, required expensive medication, developed eye issues, or worse. As in, far too many people are not mature enough to own pets. Sadly the same could be said for many having children as well.