F16's aren't any better than what the Ukrainian air force had when the war started (which was all destroyed fairly quickly), especially the export version of the F16. Fighter jets have essentially been made obsolete by modern air-defense systems, especially Russia's. Russia and China learned long ago that they couldn't compete with US development of billion-dollar jets and ships and instead focused on advanced radar plus 5-figure missiles that blow the shit out of those billion-dollar jets and ships and stockpiling massive numbers of them. Cheaper drones that just carry hand grenades have changed the game even more. While the US still builds billion-dollar jets and ships (because those are really just a domestic jobs program, not military defense).
I have a feeling that NATO troops will eventually be deployed and that will highlight how little we actually care about Ukrainians since we'll wait until half a million of them are dead first.
AA hasn't made fighters obsolete. Russia is relying heavily on traditional fighters, bombers, and choppers in Ukraine. The deal in modern combat since WW2 is that you can't go on offense until you have air support, and you can't have air support until you can deal with enemy AA. NATO won't and can't give Ukraine the ability to overcome Russian AA, but they also want Ukraine to go on offense, because politically, they can't and won't negotiate a truce with Russia, so what they've chosen to do is twist their dick around and jam it up their own asshole.
Russian AA isn't invulnerable. We have radar-hunting missiles and all kinds of cool shit to blow up Russian AA. But, as with these fancy tanks and HIMARS systems we're sending them, we cannot and will not send them to Ukraine in the volume needed to win a war, because, whoops, it turns out you need a fuckton of resources to do that. Just look at Abrams tanks. If we were to field those in volume in Ukraine, the big boy version that is actually meant to go up against Russian equipment, maybe 500 of them, that's $12b in tanks. $12b is six times the annual budget we spend on
ourselves in tanks, and nobody is out there accusing the USA of being thrifty when it comes to our military budget.
Then throw on top of that the fact that we will not send Ukraine any cool shit if it could get captured. They can have HIMARS systems, because those strike from far away. They can't have the good tanks, because those are front-line fighting vehicles, and Russia might snag one. So that's another lesson everyone's learned. The USA might have some badass miltech, but if there's a ghost of a chance we might actually lose something to an enemy, we won't even deploy it. You're safe.
The lesson here is more subtle than "US equipment is obsolete," because it isn't. It kicks ass. The lesson is political - Uncle Sam is simply not going to deploy the best American stuff at volume in a theater we don't completely control. We sent I think 109 Bradleys to Ukraine. We sent 2,200 to Desert Storm. What the fuck are you supposed to do with 109 Bradleys on a 300-mile front and no air support? Oh, it turns out what you do is get killed by Ka-52s.