When I first got into rescue, I questioned the whole point of it. After all, if rescue groups are not convincing people to adopt instead of buy, then they aren't changing the number of animals being saved. If you have a surplus of animals in shelters, and you euthanized all of them and started over with zero, within a few weeks you'd once again have a surplus of animals, with or without rescue groups. And if people were willing to adopt a pet instead of buying one, then why not just let them go to the city shelters to get the exact same animal that they'd get from a rescue group? So here's what I found.
A) Rescue groups help by bringing the pets to people who may not want to go to a shelter environment. With offsite adoptions, people get the chance to see the animals in a more friendly environment than some of the underfunded city shelters, thus promoting adoptions.
B) Rescue groups help by increasing adoptions to people who aren't aware that there are animals who need them. If animals are kept in shelters, they are "out of sight, out of mind". By putting them out in public view in places like PetSmart and PetCo, they have a better chance of being adopted.
C) Rescue groups can help rural and city shelters that don't have funding to do adoptions. The people who are hired by the city to work at a shelter may have been hired to do several other jobs as well - animal control may only be a small part of their job, and they may not care about the animals they take in. When rescue groups come along and take some of those pets, they give those pets a chance for adoption that they would not have had otherwise.
D) Rescue groups who provide foster care to the pets in their care can help make certain pets more adoptable. Many animals such as the very young, or those who are sick or have physical handicaps cannot survive in a shelter environment. And some pets have behavior problems that make them unadoptable in a shelter environment. Foster homes can give these pets a second chance for finding an adoptive home. Foster homes also can learn more about the animals they're caring for, thus providing more information to prospective adopters and reducing the number of animals returned.
I'm sure there are more reasons that rescue groups are needed, but those are the biggest ones I think. I believe that rescue groups DO increase pet adoptions, thus saving lives. They also work within their community to reduce pet overpopulation, and help people resolve issues with their pets in order to keep them, instead of turning them into shelters. Most of the small rescue groups are 100% volunteer run. That means there are a lot of people like me out there, who spend every spare moment that they aren't at work caring for homeless animals and making their lives better, without any pay or benefits. Which leads me to the question of why I volunteer.
And that can be summed up in three words. I love it. I occasionally ask someone to volunteer with me, but most of the time, I don't. For the same reason I don't ask people to adopt one of my fosters, or to foster an animal (except for Scribbles - I'm desperate here!). Because if you don't love it, you won't enjoy it, and you won't keep doing it. I don't volunteer with children, or with horses. I like kids, but I don't think I could handle working with them all the time. And horses just scare me. So I understand people that can't imagine taking care of homeless dogs and cats. Because if I didn't love working with them, and making such a difference in their lives, I wouldn't be able to do it.
It's not easy - rushing home from work to take care of the animals, and giving up vacation days to take them to the vet, and giving up every Saturday to take them to adoption events. Sometimes I wonder why I'm giving up my time to take care of someone else's dog because that person couldn't be bothered to call a trainer, or visit a vet instead of just abandoning their dog. I may find myself trying to remember how it went from "let's just foster one dog as a playmate for Remi" to this. But then I get an e-mail from a previous adopter, telling me how well their new pet is doing and how much they love him. And then one of my foster dogs looks at me like I'm their hero (which could be because I'm holding a treat in my hand, but I'll take what I can get). And one of my foster cats jumps in my lap and begins purring... and I remember again why I do this, and how much I love it. And at the end of the day, I can look back on my day and be satisfied that I did something worthwhile.