The A-10 is obsolete. Its airframe literally can’t hold the power systems required to support modern defensive and offensive capabilities. It would get wrecked against any modern air defense environment. It was designed for the threat environment from half a century ago with no upgrade path.
F-15 and F-18 are not better at air superiority. The latest flavor of F-15 can still hold its own against other 4th gen aircraft but it will struggle against 5th gen aircraft. This has been demonstrated many times.
The F-35 can carry much more weapons payload than any of the 4th gen aircraft you mention and has more range. That on its own is a huge win, stealth and sensors notwithstanding.
You don’t seem to understand the criteria against which military aircraft are judged.
F-15 and F-18 are not better at air superiority. The latest flavor of F-15 can still hold its own against other 4th gen aircraft but it will struggle against 5th gen aircraft. This has been demonstrated many times.
The F-35 can carry much more weapons payload than any of the 4th gen aircraft you mention and has more range. That on its own is a huge win, stealth and sensors notwithstanding.
You don’t seem to understand the criteria against which military aircraft are judged.