According to the internets, Ukraine is pumping out drones at about $300 to $500 at a rate of several tens of thousands per day. Of course a missile is faster and has bigger payload, but as a sibling comment mentioned, a javelin missile is about 500x more expensive than these cheap drones and can only hit target per missile. I can think of many scenario's where having a few hundred drones available to hunt down individual soldiers would be much more valuable that having a single javelin.