All banks in the US are required by Federal banking regulations to positively identify. Some banks do it up front others have a threshold of dollars transferred in and out. I believe Apple Cash threshold is a cumulative total of $500.
The Patriot Act requires that lenders, banks etc. obtain a confirmed ID.
“To help the government fight the funding of terrorism and money laundering activities, Federal law requires all financial institutions to obtain, verify, and record information that identifies each person who opens an account. What this means for you: When you open an account, we will ask for your name, address, date of birth, and other information that will allow us to identify you. We may also ask to see your driver's license or other identifying documents.”
https://applecash.greendot.com/termsconditions/
Title III of the Patriot Act