Stealth is still susceptible to infrared, which is what Ukraine was using to shoot down Russian aircraft at the start of the war.

If your CAS needs to get into visual range, it's fucked. If it doesn't, the usefulness of stealth gets called into question (particularly because, y'know, the entire point of CAS is to have a big bomb to drop on someone, and strapping that to a mounting point ruins your stealth profile).