What's the point of American police saying "Show your hands" after they shot a man?

Because it's harder to pick and choose trial evidence that exonerates the cops of their malfeasance unless you have something evidencing that they told them to stop before they fired their gun, regardless of whether they actually said it before firing their gun.

A(A)CAB crew checking in, I guess, without a solution in hand. Show me a solution without cops and I'll show you a warzone.
- show me a solution without cops
  
  when my car got stolen and the cops just gave me a report number and then me and my insurance did literally everything else
- I don't think in general the ACAB crowd means "no police". It means better training, independent oversight, and a division of roles (e.g. social work, welfare check).
  
  Basically actually having accountability would go a long way towards weeding out the root problem
- My apartment was broken into and stuff stolen. The cops came, took notes, took one of my vases for evidence (which they lost), then left.
  
  So besides stealing even more of my shit, and providing paperwork for my insurance company, what exactly did they do?
- Germany, Switzerland.... Finland...
  You know... Free countries

Wounded people can still shoot you back/stab you. They may even be more likely to do so due to the shock and adrenaline rush. Also the fact that one has been shot indicates that they probably had something in their hands in the first place or were unwilling to show that they didn't.

After they've been shot, lethal force has already been determined to be necessary. Cops don't stop until they stop moving or they're making it very, very obvious they surrender. (side note. Having something in your hand is not justification for lethal force. 'I thought it was a weapon' as an excuse has worn too thin. but they'll say other bullshit too like, 'they had an aggressive posture' and 'were verbally combative'. )

Also, people typically fall back on their training in stressful situations, and they're taught to shout things. like "show me your hands" ... a lot. they may not even be entirely aware of why they're shouting it. or even what they're shouting. (Cops have been known to yell some freaking dumb shit after shooting people. You see the videos of them yelling "Get on the ground" when the dude is already... on the ground? just saying)

If the person is able and willing to surrender after being shot, showing their hands (empty of anything they may have been holding before) and following instructions means the police can start first aid and bring in EMS sooner. The ambulance doesn't come in until it is safe to do so which won't be until after a search is done and handcuffs are applied. Specific details beyond that and exceptions to the norm would depend on local policies.

Assuming there was ever anything in the victim's hands to begin with. Plenty of cops will go on to deny the person emergency treatment under the guise of the individual being "too dangerous"

Edit: To anyone daring to question the veracity of this statement, just go ahead and watch the last moments of this man's life then take a good long look at yourselves and think about just what you're trying to defend here. This is nothing but murder. Decided on by an overly-sensitive EMT and endorsed by six different cops. Be ashamed of yourselves.
...So if you use your hands to put pressure on the wound to stop the bleeding, you won't get an ambulance?
- No, but it's going to take longer for them to confirm the scene is safe for first aid and paramedics.
By the way, I'm wondering who pays for the ambulance in this case? Suspect or government?
- In normal countries, normal people don't pay for use of emergency services.
  
  What kind of hell do you live in where an ambulance is a cost/benefits equation?
- Just a guess, but I'd think it'd be based on fault. If it's a justified shooting, they'll probably tack it into the suspect's fines. Ideally, if the shooting isn't justified, the govt would pay, but I wouldn't count on it.

To have a court excuse in case they shoot again. "Didn't comply. Hid hands. I felt threatened."

Like the guys who literally get away with murder on film need an excuse.
- It helps the murdering cop if it is one of the extremely few shootings that makes it to a jury.
- They don't but it makes their fragile egos feel better if they have one lined up

Ever hear about medal of honour winners killing 12 people with 5 bullets in them? Bullets aren't always show stoppers

Add some meth or fentanyl to the mix and it's sadly pretty much zombie rules to put them down.

this is why cops dump entire mags without thinking.

that and most of them can't actually shoot for shit.
- Yep:
  
  Nine bystanders were wounded by stray bullets fired by the officers and ricocheting debris, but none suffered life-threatening injuries.
  
  https://en.wikipedia.org/wiki/2012_Empire_State_Building_shooting
- Or think for shit
- You say that but most cops still will go their whole career without firing their gun statistically.
  
  Plus hand guns are crazy hard to aim over any distance
I saw a body cam video of a female officer confronting a (probably homeless) dude hopped up on drugs. She was on her own in this situation without backup which was fucked up in it's own right but this guy just keeps walking towards her closer and closer. Eventually she draws, warns him she'll shoot if he gets closer and ends up firing twice.

This guy took two rounds to the chest at damn near arms reach and barely even fucking blinks. He turned around, walked to a corner, layed down and died there iirc (here's the vid https://youtu.be/8oX2ChamWwc?feature=shared)
- It’s possible that a less lethal response would have not only been more appropriate but more effective

I'm going to guess they are terrified and excited and just yelling random cop noises.

To shoot you again in case you are still alive

This post has no business in this community

[Edit because everyone seems to disagree] OP posts these charged questions without clear answers all the time. They're not earnestly asking

Bad faith actor. Gotcha.
- Yeah. Check out their post history, they're clearly just fishing for replies with charged post titles