Endless War

“During that big attack by Iran on Israel, the U.S. didn’t send any F-35s. We sent F-15s. Why didn’t we use F-35s to defend against the Iranian attack?” he asked.

Russia is also shy in using its 5th gen aircraft. Expensive asset + expensive flight time maintenance, and embarassment of failures are likely similar factors.

As to boasts about F35 use vs Iran, there were reports that Israel was planning a 3 wave attack, and that it stopped at first wave, had reports of planes getting "lit up" with radar/air defenses. Maybe Israel are just nice guys showing restraint.