Fighter jets are broken

So I generally agree with you and I felt the same way but I kept practicing with the jet (both jets) and I have to say that they can actually be extremely powerful in air-to-air combat. Last night I destroyed 14 vehicles (all air btw), the next game I destroyed 10, and the game after that I destroyed 12; there was one game where I went 5/5 in dog fights against other jets (though to be fair dog fighting is really bad in BF2042 - it basically becomes who can get behind the other jet first, that's who wins). 

Some constructive feedback is that the jets can actually turn much quicker than you think (don't need to do wide sweeping turns) and that you should take more risk in re-engaging helicopters right away. Generally what happens is that you lock on with one AA, fire, enemy heli flares. So what I do is I fire the first AA then immediately swap to cannons and attempt to get a few bursts in (doesn't always work but that just an aim practice thing), but as soon as I pass the heli I immediately bank while holding S (or back petal for on foot - whatever that is for you) - that is essentially hitting the e-brake in a car and you turn relatively quickly. Most of the time I can turn sharp enough to re-lock with AA and fire while the heli flares are still on cooldown. At that time I am confident that I will take the heli down because now the pressure is on the heli pilot. They have to decide whether to run and hide (which takes them out of the fight rendering them effectively useless), or continue their original course. But you can keep applying the pressure with your jet e-braking and eventually take out the heli without having to fire cannons. It can be really satisfying actually - I've noticed that if you can establish early into a round that you are the apex predator (I know that's a title and I'm using it purposefully here) with the jet, the enemy team tends to stop using helis or uses them infrequently because they know that you will hunt them down immediately. 

As it relates to anti-ground vehicles and infantry, I 100% agree that jets tend to feel useless. I haven't practiced much with AGMs, but I do know that a good jet pilot using AGMs can be deadly to ground vehicles - I just personally don't like feeling vulnerable in the sky because my cannon aim needs a lot of improvement, so that is why I don't run AGMs over AA. I will contend though that the primary purpose of jets is NOT to be anti-infantry - that is what helicopters and ground vehicles are more aligned with. Jets, from my perspective, are primarily anti-vehicle. When I'm in the jet the only thing I am worrying about is protecting my infantry from helicopters. That's my role - my role isn't to rack up high infantry kill counts - my role is to dominate the sky so that my infantry can focus on ground vehicles and enemy infantry. 

Don't give up on the jets just yet - they take time and practice to become effective and once you've started to get the hang of it, flying a jet will become very addictive because of how satisfying it is to control the sky.