There are legitimate reasons to want a camera either at your front door or surveilling your property. These can range from an increased sense of security to having documentation to support insurance claims, or even for watching wildlife. We installed our Ring camera after an ongoing string of nighttime car break-ins hit us and we had no direct proof of what happened for insurance. It was meant to be both a deterrent to that type of event and also for documentation if it happened again. There's also a pack of coyotes that lives in the woods near our house and occasionally eats our chickens. While that usage was more out of curiosity (if you have chickens, you're going to lose one from time to time), we were able to develop a sense of when that threat was higher.
I live on a bucolic cul-de-sac in a house that I've lived in since the mid 1970s. Most of the neighbors are the same. I never in my life expected a random person to drive down the street, drag a lady out of his trunk, chase her around the cul-de-sac, and stab her to death in front of my house. I never expected to find the body in the woods 40' from my side door. This is when I also learned that nobody comes to clean up after a crime like that and that if I didn't want pools of blood in front of my house and a 50' streak of it crossing the circle or the splatters all over the mailboxes that I was going to have to go out there and clean it up myself. I was in PTSD therapy for a while after that. I'm glad the Ring camera caught some of the activity.
After an event like that, it's easy to lose a sense of security in your home. How are you supposed to sleep the night after that happens, when the perpetrator remains at large? You can't lock your doors hard enough or do anything at all to feel secure. That lack of sense of security does not go away in a day or a week or a month. It goes away when you can find "normal" again. It helped us to find normal by installing other cameras around the house.
I don't want Ring or Arlo or anybody to be automatically sharing my camera footage with anybody. Even with the murder event, it was my choice to go through the footage and share it with the authorities. I don't support authoritarian "law enforcement" activities, I don't want anybody tapping into my camera feed to find lost pets or for any other reason. They shouldn't be allowed to do it. Like many other services we all use, we're more of the product than the customer, as our data is harvested and used for other purposes.
Personal security is different than targeted advertising. Most people won't know they need or want a camera until after they have experienced something that makes them feel less secure in their home. I just hope they have the wits to read the Terms and understand what they're opting into before automatically accepting all of the opt-in-by-default data sharing.