The A-10 has limits against high end threats. However, for everything else it is highly useful. Spent some time with an A-10 training unit many years ago and got a good look at the systems and capability.
Today, it is even more capable with E/O pods and modern precision guided munitions. Slow response for 911 CAS if it isn't nearby but then, nothing is perfect. You won't see the F-35 doing this anytime soon. If ever.