Although the narrative for overhauling systems of policing varies city by city across the United States, one thing to keep in mind is that defunding does not necessarily mean dismantling.
Defunding the police means diverting funds from police budgets to social services and education to better serve community interests. It is often lower income neighborhoods in the US that see the most police presence. The aggressive approach to over policing lower income neighborhoods and neighborhoods predominantly populated by people of color leads to mass incarceration of black and brown bodies, often for low level crimes. Once incarcerated, these individuals are often forced into unpaid labor while those who own the prisons profit.
The US prison system is a privatized, for profit institution.
Tax dollars paid by BIPOC or lower income communities are weaponized and used directly against them to further the economic benefit of the wealthy elite.
In light of all the police violence, if you believe more funding is needed for proper training. Let's talk about it. But I urge you to look at the police response to peaceful protest in the US, and read my post about the origins of policing in the US.
Lack of funding is not the issue, it is that the police institution of the United States is built on a system of profiting from racialized violence.