AUs will get credit limits which make their utilization low. Utilization accounts for up to 30% of FICO score. They will get a payment history starting from when they get the card as well. It's good for people who never have a card before or those who have a very low credit limit and/or low FICO score.
I added a friend who had an issue getting a credit card there. He got just one card with a $500 limit and 5xx Fico. Utilization was always high. Adding my $10K limit, and after some months, he ended up with 66X and it is easier for him to get more cards on his own now. His score dropped a bit when my utilization was high.
There are so many Americans who are struggling to get a credit card while their banks give a massive credit limit to us lol