You are focusing on a single point, while you are right in some ways, the F-35 is battle tested, the IAF operates them within Syria very frequently, the F-22 Has flown escort missions within Iran, escorting UAV's and warding off IRAF aircraft. The SU57 and J20 are not however, you are correct. But if you have a platform of a similar role and capability that is tried and true and has been in service for decades, why go for the other? On cost grounds, the gripen has no edge. Diplomatic terms, Gripen has no edge, it does have a superior weapons loadout on paper, it does not have the same developed supply chain like the F-16 has. There is literally no reason to go for a Gripen instead of an advanced F-16 variant or the F-35. Also, just a simple example, on paper, the RVV-AE(export variant of the R-77) is highly lethal and capable with stellar range and kinematic performance, however, in reality, as we had learnt on February 27th, it is nowhere as capable as the specsheet says and cannot perform as expected.