We do that when we can. I had the momma cat spayed this summer . That's why we are down to only one tomcat now. Luckily there's a vet nearby who gives us a quantity discount.
She was a terrible mother. Kept having her litters in the yard and leaving them when it rained. I tried to save the kittens she abandoned that way but they all died. Not long after spaying she disappeared. Most likely got caught by the coyotes. A lot of cats in the area have gone missing this winter.
Spaying and neutering keeps the population manageable but we live in a very rural area with a lot of farms. Whenever the population on one farm gets too low some of the cats from the neighboring farms move in. I've found over the years that the best method is to leave the cat population alone as long as it's generally healthy. The only time I intervene is when one is sick, injured or in the case of an abandoned kitten or if there's too many. For the most part the outdoor cat population is wild and it's best to treat it as such. Besides the main killers around here are coyotes and the road and there's not much you can do about that.
Our orange cats are the legacy of a tomcat we found when we moved in over 30 years ago. The people who owned the house before us had a momma with a litter of kittens. They took the momma cat with them when they moved and left the kittens who were too young to be on their own. A neighbor found them in their barn too weak to run away except one who apparently had managed to catch enough insects to stay strong. I was 10 when we moved here and spent the summer taming him. By tame I mean that only in relative terms. I could pick him up but when my mom tried to pick him up once she ended up in the ER with six stitches in her finger. He became the dominant tom and over the next eight years almost all the kittens in the area started to turn up orange. Orange cats around here are still some of the best mousers.