Why is C-Cl bond in acyl chloride more reactive despite being highly polarized?

[AryaUnderfoot]

For acyl chloride the very electronegative oxygen atom attracts electrons of the carbon atom, thus greatly polarised the C-Cl bond. But won't it attract electrons of the Cl atom too? Then with the electrons drifting towards the C atom, it's partial positive charge should be reduced, but why is that wrong?
Also, since the C-Cl bond is greatly polarised, the bonding should be stronger, isn't it? Like C-F bond is more polar than C-Cl bond, so the fluoroalkane is less reactive than chloroalkane, but why is that acyl chloride, with its very polarised C-Cl bond, so reactive?
And for chlorobenzene, the electrons on halogen atom are delocalised into the benzene ring, causing the polarity of C-X bond to decrease, but why is it that the bond is stronger than haloalkane?
I realize that this is a very long question, thank you for your patience

 

[Borek]

Chlorine electronegativity is not much lower than that of oxygen.

 

[AryaUnderfoot]

Chlorine electronegativity is not much lower than that of oxygen.

I don't understand

 

[Borek]

You can't assume oxygen draws the electrons from the carbon, and chlorine doesn't.

 

[AryaUnderfoot]

You can't assume oxygen draws the electrons from the carbon, and chlorine doesn't.

Ohhh, I got it
But what about the next question? I thought the more polarised a bond is, the stronger it is, so it's less reactive?

 

[Silicon Waffle]

For acyl chloride the very electronegative oxygen atom attracts electrons of the carbon atom, thus greatly polarised the C-Cl bond. But won't it attract electrons of the Cl atom too? Then with the electrons drifting towards the C atom, it's partial positive charge should be reduced, but why is that wrong?
Also, since the C-Cl bond is greatly polarised, the bonding should be stronger, isn't it? Like C-F bond is more polar than C-Cl bond, so the fluoroalkane is less reactive than chloroalkane, but why is that acyl chloride, with its very polarised C-Cl bond, so reactive?
And for chlorobenzene, the electrons on halogen atom are delocalised into the benzene ring, causing the polarity of C-X bond to decrease, but why is it that the bond is stronger than haloalkane?
I realize that this is a very long question, thank you for your patience

Both C=O or C-O and C-Cl are polarized, Oxygen does attract e from Carbon towards itself, and so does Chloride, which leaves the positively charged carbon atom to be easily attacked by nucleophiles (e.g water).