Police overhauls swept the country after George Floyd, but fell short, activists say.

Specific steps that have been enacted or considered include bans on chokeholds, limits on no-knock warrants, requiring officers to wear cameras and tightening use-of-force rules, as well as overhauling disciplinary procedures.

Colorado passed one of the nation’s most sweeping packages, influenced in part by the deaths in custody of Mr. Floyd and Elijah McClain, who was stopped by officers in Aurora, Colo., placed in a chokehold and injected with a powerful sedative. He died a few days later.

In 2020, the city of Memphis enacted its own policing overhaul, voting to require the Memphis Police Department to adopt policies meant to reduce the use of excessive force by officers.

Even so, activists argue that across the country, the progress has been too slow, and police brutality remains endemic.

“When we look at what’s happening overall and the landscape of police violence, it seems to be getting worse and not better,” said Samuel Sinyangwe, founder of Mapping Police Violence, a nonprofit research group.

American police officers killed more people in 2022 than in any year of the past decade, according to an analysis by Mr. Sinyangwe’s organization. Not all the killings are the result of inappropriate use of force. The analysis noted that 26 percent of the people killed by the police in 2022 were Black, though only 13 percent of the U.S. population is Black.

Some police agencies have moved to hire more nonwhite law enforcement officers to reflect the communities they serve. But activists emphasize that reducing police violence is more about changing the way the criminal justice system views Black people than about who is doing the policing. All five officers charged with killing Tyre Nichols are Black.

“It doesn’t necessarily matter about the police officers’ race when the police officers are being indoctrinated into a system that is, in part, systemically racist and biased,” said Charles Coleman Jr., a civil rights attorney and former Brooklyn prosecutor.

Rashad Robinson, chief executive of Color of Change, a racial justice organization, said: “At a deeply structural level, policing in this country has been designed to control and to harm and to hurt Black people. You cannot change that issue simply by diversity.”

“True public safety isn’t about charging police officers after heinous acts like this,” he added. “It is about actually ensuring that institutions that are supposed to keep us safe actually do that.”

Even though some state and local jurisdictions have changed their approaches to mental health incidents or traffic stops, some activists believe that hostility from law enforcement toward any changes to policing has contributed to the rise in police violence.

Mr. Sinyangwe called it a “backlash” in which “the police are sort of responding to calls for accountability and calls for reform with doubling down on the types of policies and practices that got us in this mess.”

Mr. Coleman pointed to Congress’s failure to pass the George Floyd Justice in Policing Act of 2021, which was approved by the House but stalled in the Senate, as a profound setback for police reform. The bill would have, among other things, banned chokeholds and ended the qualified immunity defense for officers who are sued. On Thursday, President Biden renewed his call for Congress to pass a policing bill.

Mr. Sinyangwe said the federal bill had some good provisions regarding standards for transparency and data collection, but was limited in its capacity to reduce police violence. “That’s not going to change the game,” he said.

He cited Denver’s STAR Program as a more effective approach to reducing police violence. That program sends emergency medical technicians and behavioral health specialists on calls about people having mental health episodes — calls that previously would have been handled by police officers alone.

Audra D. S. Burch contributed reporting.