Credit age / churning question

Hey y’all. Searched the thread but couldn’t find a concrete answer. I’ve had credit cards for more than 7 years. I recently got into the rewards / sub game and loving it. My average age of credit is just under 3 years. Will opening a new card affect me that much more? Got the gold Amex for the SUB and considering closing after a year. I really want the green card for the buffed SUB but worried about the age of credit. Any insights? Again sorry if it’s noobish!