Partially true, the calculation is as such, if one drone can destroy more than two targets before being shot down then it is worth it. A T-72 tank is 1.5 million, if you destroy two of them you incurred 3mil in losses while the drone costs around 1mil. Add to that, Azerbaijan has way more money then Armenia. Therefore, the strategy of Azerbaijan is to destroy as much as they can in the first 2 weeks or so, then they will start with offensive infantry/ special forces, etc. missions. This is all to lure in Armenian reservists and equipment and take out as much as they can. Drones sometimes do more psychological damage than anything else, you never know when you're next or if "they" are watching.