I think you must not have interacted with many people who advocate for police abolition. Even just googling "abolish the police" returns a page full of results of various proposals, with detailed breakdowns. It's quite simple: just how we don't call the police for house fires or heart attacks, there are a large variety of other societal problems which would be better served by more specialized (and less heavily armed) services.

Also, police exist to protect capital, not us. It evolved from slave catching forces, and does relatively little to prevent or solve most crime.