I play in the Asia (Japan) region, and I have never felt that anti-air missiles were useless.
I occasionally pilot helicopters and jets myself; if I get targeted by a lock-on launcher, I have to pop flares and quickly duck behind cover—like a mountain—or flee as far away as possible.
Since it is impossible to attack the enemy while on the move, this need to retreat gives enemy ground forces an opening to advance.
Why not view these weapons not merely as tools for annihilation, but as a means to keep the enemy wary and halt their advance?
Speaking as a pilot, surface-to-air missiles are a real nuisance. Even having just a single one fired at you is a major hassle.