Given: There WILL be cops ...

... and by cops, I mean organized efforts to impose legal restraint upon everybody.

The inescapable failure inherent to this whole "defund the cops" idea is that it completely reverses the problem. Cops enforce the laws of the legal jurisdiction that employs them. If you want cops to enforce laws differently, change the laws cops are required to enforce. Change the training cops receive so as to change the ways and means they are trained to use to enforce the laws. Change the courts so as to remove the unlawful separation of responsibility from actions taken ("qualified immunity" has no basis in written law, but is instead the intended result of the US Supreme Court ruling in  Harlow v. Fitzgerald, 457 U.S. 800 (1982)  ,and is generally defined as follows:

"Specifically, qualified immunity protects a government official from lawsuits alleging that the official violated a plaintiff's rights, only allowing suits where officials violated a “clearly established” statutory or constitutional right. When determining whether or not a right was “clearly established,” courts consider whether a hypothetical reasonable official would have known that the defendant’s conduct violated the plaintiff’s rights. Courts conducting this analysis apply the law that was in force at the time of the alleged violation, not the law in effect when the court considers the case.

Qualified immunity is not immunity from having to pay money damages, but rather immunity from having to go through the costs of a trial at all. Accordingly, courts must resolve qualified immunity issues as early in a case as possible, preferably before discovery.

Qualified immunity only applies to suits against government officials as individuals, not suits against the government for damages caused by the officials’ actions. Although qualified immunity frequently appears in cases involving police officers, it also applies to most other executive branch officials. While judges, prosecutors, legislators, and some other government officials do not receive qualified immunity, most are protected by other immunity doctrines."  See: https://www.law.cornell.edu/wex/qualified_immunity

 IANAL but "qualified immunity" seems to be an obvious extension of "judicial immunity" by the Supreme Court which itself is a matter of written law (see: https://www.law.cornell.edu/uscode/text/42/1983).

Is this a desirable condition of American jurisprudence? Call or write your state's Attorney General's office, call or write your state's Governor's office, call or write your Member of Congress and your state's Senator's offices, register your opinion and legislative desires with them. Make your voice heard, agitate with those who have the ability to make the needed change(s). But do so from an inescapable minimum condition of existence; there will be cops, because we need cops - preferably one's determinedly working from a clearly delineated position of neutrality between the generally conflicting interests of members of US society.

The assertion that "the law is what it is" is probably made only slightly less frequently than is "the law is an ass", but equally inescapably, the law is ... and in some form or another will continue to be. That being so, it is desirable and necessary to frequently review the law, and those who are employed to enforce it. Not just cops, prosecutors, and judges either; there is a serious argument being made that the US (at all levels of governance, not just federally) has too many laws, too many of which are already part of previously existing legislation (which is how a law is legally made - executive orders that do not specifically reference an enabling act of legislation do not have force of law no matter how hard or often a Governor or President says otherwise).

Changing the laws of the US (again, at all levels of governance) would be the most certain means of reforming police interactions with the general public. Changing police training to reflect the enforcement requirements of the law would complete the reform process. Doing all of that at the federal level would almost certainly be necessary to achieve at least some degree of national uniformity of enforcement (and achieving that degree of uniformity would itself be a drawn out process, if only due to the complexity of competing interests inherent to the multi-level nature of US legal and political structure). While a dramatic performance before the House Ways and Means Committee demonstrating the sheer volume of federal legislation (and how much less is actually required to achieve the same - arguably better - levels of public protection) would certainly be entertaining, the reality is this will be a long and contentious effort requiring multiple iterations of change.

Personal note: I lived in S. California during 1991 and '92. I'm quite familiar with the events surrounding the arrest of Rodney King and the prosecution of his arresting police officers (I lived roughly a mile away from the arrest scene). I fully expect that the essentially identical legal process will play out in Minnesota, probably during the 2020/21 winter months (for what I regard as obvious reasons). The officers will be found "not guilty" by reason of qualified immunity in state court, and in very short order thereafter found "guilty" in federal court of violating George Floyd's civil rights, for which they will be imprisoned for a number of years. It goes without saying that Floyd's family will receive a financial settlement from Minnesota.

If we are going to achieve this change in US laws and how they are enforced, and I agree that we should if we wish to continue as citizens of a recognizably USA, then we must begin to organize the mechanisms necessary to doing all of that.

Or, we can just go ahead and form the national circular firing squad and do it that way.