A ground attack jet needs ARMOR, not stealth.
A large payload capacity is a must.
TWO engines is a must.
Funny thing about the A-10. It’s principal designer was the infamous Col. John Boyd. Now Boyd his famous for his theories of maneuverability leading to the F16 and derivatively the F15 and F18 (though the latter two were heavier and less maneuverable than he believed you needed). So he was branded as an advanced fighter advocate in an Air Force that wanted to do strategic bombing. Then they asked for a good ground attack, direct support aircraft. He looked at what attributes were needed (firepower, survivability) and voila the A-10 a great airplane for its mission.