Kali Raspberry PI 3 - 8G or 14G

I've downloaded the image from the official site, for raspberry pi 3. The xz file is 2.1GB. But when extracted to its image file, the size has increased to 14GB. The documentation says that we need 8GB SD card. Something doesn't adds up. Obviously transferring a 14GB image to a 8GD SD card doesn't work. It transferred 7.7 GB before failing. Can someone help explain what is the actual SD size requirement? Is the documentation outdated? I cannot seem to be able to create Kali on my 8GB card.
Thanks

I had the same issue, it's end it up with using a 32 GB.
I used a 64 GB first, then I used a 16 GB and it woks just fine, lastly I used a 32 GB both the 16 & 32 worked, but not the 8 GB & 64 GB.
hope this can help you
BTW, I'm using the raspberry Pi 4 8GB