Defund the police is stupid. A country needs a functioning police force to have a functional society. Even most libertarians, wanting as little state as possible, agree some form of police is necessary.
The problem is the police in the US have too much power. Their unions and fellow officers protect each other. It doesn't matter if there are just a "few bad apples" if they all shield each other from scrutiny. As @dunkemhigh says, we are in an increasing age where everyone has a phone, CCTV, and officers in some states are required to have body cameras.
In the UK, in order to become a police officer you need to hold a degree or an equivalent form of higher education. Whereas many police departments in the US expressly prohibit police from having any form of higher education. Why is this? It's as if the administration want dumb worker bees, not someone who can think on their feet and respond appropriately, de-escalating where possible. It seems in the USA, police govern by force, whereas in the UK and in many other countries, police govern by consent.