My old PS4 data got deleted but my friend's didn't. I was wondering if I could move his updates from his system to my PS4.
I have really bad internet that's why I am asking.
This is not possible.
The PS4 deletes patch files once they have been used to update the base game files so there is no file on your friend's PS4 that can be manually transferred.
Even if you could get a hold of the patch file from another internet source, there is no official support for manually updating a game via USB on PS4.
What you can try to do is transfer the entire game data from your friends PS4 to your PS4 using an external hard drive. This has it's own problems though,
It is not possible to copy a game data from the system hard drive to the external hard drive using the PS4. You can do this by manually plugging the PS4 hard drive in to a PC to get around item 3.