To be clear, that F35 was being incredibly careless, flying low in broad daylight. All the stealth features of an aircraft are useless if you can look at it with your own eyes. In any conflict with China, F35s would not be flown that way.
You're holding it wrong?
How many cheap-ass drones could you buy for the cost of one F35. 100k? A million?
To be clear, Trump announced that the US had destroyed Iran's air defenses, missiles and missile launch capabilities. Trump also said that the US enjoyed air supremacy over Iran and were flying when and where they wished.
Maybe one of these days we'll see a B-52 take off with JDAMs and not JASSMs but probably not, kind of scary to try and drop gravity bombs on a country that your stealth fighters can't fly over.
In a direct conflict with China, the ICBM exchange would destroy the F35s on the ground.