The Ukrainians are operating SU25 now in uncontrolled air space. The A10 would offer a fresh fleet capable of carrying a much wider range of weapons.
Yes, the Ukrainians have lost some good pilots flying those planes in uncontrolled airspace, they're vulnerable even to basic manpads

299th Tactical Aviation Brigade - Wikipedia
Scroll down and you can see the losses they've unfortunately taken, the men lost in those planes are not easily replaced