The A-10 was built around it’s 30 mm cannon but it’s vulnerable while using it. During the Gulf War (or should we call it the First US-Iraq War now?), A-10 pilots often used missiles to hit targets from outside the range of AAA and shoulder launched SAMs. The LANTIRN pod wasn’t around yet so they’d use the feed from the IR version of the Maverick missile to find vehicles. A new plane built for the CAS/BAI (Battlefied Air Interdiction) mission might still have an internal cannon(s) but will definitely be able to use a wide range of missiles for situations where targets are defended.