I feel like nobody complaining here has ever tried to fly anything in BF6. You get locked non-stop from the time you spawn. If the broad ground-based anti-air options were all as potent as this thread seems to believe they should be, air vehicles would be incapable of impacting the game. For several BF titles now the jets have been nerfed more and more in multiple ways because of constant complaining, creating a high skill requirement just to get a few kills a game. Lock-on weapons require no skill, so it's appropriate that they shouldn't have unlimited range while also still enjoying on of the highest amounts of damage from a single hit. Hitting an air vehicle causes about 50% total vehicle health damage, creates an irratic immobilization often leading to unavoidable crashing. And, just for good measure, you not get credited with the kill if your point, shoot and forget it weapons cause that crash (because of how many jet-chasing IGLA pros complained about being "robbed" before).
Everyone wants everything they use to be better. Just suck it up and play.