Terrifying and startling people whilst pointing a gun at them and demanding immediate compliance under threat of execution is not starting off at a healthy level of escalation! It puts people straight into the depths of their fight or flight response, and then police act surprised at them when they do one of those things?
The way humans work means that a lot of the time the honest answer for "Why did you run?" is "Because you were chasing me!".
And in the USA traffic stops can start with firearms drawn! This is not a slow escalation and an aim to de-escalate. When things start with hands on firearms, it's already escalated to the extreme. Which is the problem, rather than approaching people like...people, American police are taught to approach everyone as an immediate and significant threat. But when you start treating someone as a threat, the only direction for things to go is worse.
I personally know white people in the USA who have said they wouldn't call the police if their house was burgled because they expect the police would treat them as roughly as they would treat the burglar. That's fucked up.
A simple question:
If you were found to have a small white bag of cocaine on you whilst trying to enter a club and a police officer were called over, which of the following do you think is more likely to happen in the USA:
A) You be calmly talked to by a police officer, asked for details and id which they note down and report, and they only resort to physically restraining you and conducting an immediate arrest if you became aggressive?
B) Or approached with hands on weapons or weapons drawn whilst being shouted at, restrained against a wall, forcibly searched, and then forced into a police car?
And which of them do you think is in the best interests of the police and society to do? And if you aren't white, are you more likely to receive A or B?