It may be a mistake to assume that drones will continue to develop and become bigger and better.
I think e.g. the Predator and Reaper Drones should be a big as they should get. At least for now. And they generally are not seen as they fly at higher altitudes.
Some of the feedback is that drones work best when small, because larger drones get shot down.
Yes at lower altitudes the smaller size gives it the advantage. And it could even use terrain masking like low flying helicopter do. Depending on the mission a number of drones may need to be employed. They even talk about at tactic called a "drone swarm". As they can't all be knocked down. Some will make it to the target.
Of course, a drone at this time could not carry the heavy ordnance load a strike aircraft or even bomber can.
There's a recent video of a Russian MTLB driving down a 'cleared lane' (marked off by engineers) and striking a mine. Either the engineers missed one, or the Ukrainians dropped a new one…
💩 Happens ! I've mentioned the event that occurred during my 2d tour on the ROK DMZ in '85.

A local farmer stepped on a mine that had been emplace there since probably '53. Those old minefields are clearly marked and cordoned off.
But somehow, someway that one was missed. How many times did that farmer or someone else walk along that location and nothing happened ? We became even more aware of this danger. How many other mines in our AO were missed ? Fortunately, no more were "found" during our tour.
So my guest is this mine that the BMP hit, was probably missed by the CEs. Human error usually covers many things.
Timeportal +1
The last word on drone tactics, etc. has not been written yet … if ever … New tech may change many things …