Start with the entirely unnessecary carniverous apex predators (aka pets) people insist on keeping. If people cant get rid of pets, then asking them to avoid replicating their own DNA is going to be a challenge.
I upvoted you, but do keep in mind that there is a lot of loneliness and some of those animals probably save us from lots of healthcare expenses. Not everything can be brought down to simple economics.
That said I have said no to dogs myself - mostly because of cost and the constant need to be looled after - and the animal we do have is a rodent that we got second hand, meaning that food cost is leftover carrot shavings etc + a bit of hay
Have you considered that for many people have pets because they don't have/can't have/don't want children? Compared to an actual human child, the footprint of a pet is quite minimal and their lifespans are short.
Well, if we need to change our diet, give up pets, give up travelling, give up individual travel in general, etc. then I think that proves the point I'm trying to make.
