When people say police have no duty to protect the public, they are talking about a legal affirmative duty to act.
Usually the law does not impose a duty to act. If you see someone drowning, it’s not negligent to NOT jump into the water and save the person. You can stand there and watch your neighbor’s kid drown and you’re neither breaking the law nor being negligent. Even if your neighbor’s kid screams for help and looks right at you and says please help me, it’s legal to do nothing: there is no affirmative duty to rescue.
It’s the same for police. The exception are when there is a fiduciary relationship, if you created the peril, or if you start rescuing someone you can’t leave them worse off. Usually these exceptions don’t apply to police, even if you call and ask for help, they have no duty to act. That doesn’t mean they won’t show up and do their best. Just means you can’t sue them for negligence if they fail to save you.
Therapists, doctors, lawyers, architects, have legal duties to act.