Often, yes. Abusers are not just people who are occasionally randomly violent. They are people who are deeply controlling, and use violence as part of that control. If you're at all interested, I strongly recommend this very readable book on abuser psychology: https://www.amazon.com/Why-Does-He-That-Controlling-ebook/dp...

It's also important to remember that our society spent centuries where women were effectively property of men. We've been digging our way out of that, but there's still a lot of overhang. The level of cultural and legal support for women leaving abusive men varies a lot from place to place and person to person.

Abusers are like an exponentially worse than a typical asshole. They have no shame and will do anything to get their way. They are highly manipulative, but at more controlling and intimate level. They get into the head of their victims to control them with guilt, shame, "love", affection, blackmail, isolation, access to children, etc and reinforce that control with physical abuse.

The manipulation makes it difficult for the victim to act. Family suspects the victim is a little unglued, Friendships are disrupted early on, etc.

Read about this guy as an extreme example: https://en.wikipedia.org/wiki/Keith_Raniere

This guy was a self-help guru type who leveraged guilt and blackmail to literally build a company around having a harem of sex slaves.

You've heard some other responses, but also consider that the abused person still often feels like it isn't that bad, and that the abuser doesn't really mean it, etc etc (usually the result of psychological abuse).

In this scenario, it's easy for the alert part of the brain to say "let's just download this app and set it up, just for the heck of it, even though I don't really need it," and it won't feel like the same kind of commitment that is needed to actually leave the relationship, or get a restraining order etc.

Or, similarly, a concerned friend could say "I know you say he'll never take away your phone, but let's just set this up, for the heck of it." Again, the victim may agree, with the one part of their mind knowing it's the right thing to do, and providing plausible deniability for the other part of their mind.

Concealed carry is not an option for many people: if you have a history of alleged crime yourself, if you live in states or counties that make that unreasonably difficult, or if you are entirely dependent on the finances and will of another person (try sneaking away for the required training and time to pass a background check when you're bordering on a human trafficking situation), it's effectively impossible. There's also wait periods. People have been murdered during cooling-off periods because they didn't have a gun until it was clear their partner wanted to kill them, but by then it was too late to wait 5 days. There's only so much the police can do about your intuition, or even a verbal threat.

Restraining orders also only stop people willing to respect them. If someone wants to commit murder, the idea of violating a restraining order marginally increasing the punishment and risk of capture changing their mind is a bit laughable.

It's a long answer to this, but I'd suggest people look up the "Wanted Podcast" episode 22 to understand similar situations better. It's 2 bail recovery agents telling a story of a skip they tracked down. She had missed a court date (probably because of her situation - being effectively forced into prostitution). She was in a terrible situation, but because of drug addiction and other psychological control in an abusive relationship, she couldn't bring herself to leave. She had called her parents for help, but then called back and told them to ignore it. One of the toughest people I've ever known hesitated to confront the man controlling her life. She had a phone at times, but it could be taken away by her captor, and when she had chances to leave she wouldn't take them. I doubt she specifically would use an app like this, but it's a case of not wanting to leave, being able to leave whenever she wants, but at times it escalates and she wants to leave but loses her ability to call for help.

It's irrational, but it happens to people.

Abuse can come with gaslighting and control of communication, so the abused may not trust that the alternative is better, or have the ability to get help quickly enough and permanently enough to avoid retaliation.

Yes, very much so. Abusers arrange for various forms of leverage over the people, ranging from emotional to financial, and then children or other dependents make everything that much more complex.