In a word, commoditization.
Regular aircraft are "expensive." They're literally expensive, in dollar terms, but even ignoring that they're logistically and operationally resource-intensive to operate. You only have so much airpower at your disposal, you're limited by flight deck space and pilot availability, you want to keep some in reserve, and aircraft are a bitch to maintain. Like, a week in service per day of flight time.
Basically, you default to not using them. You don't bust them out unless you have good reason to. You don't just cruise around looking for people who look suspicious, because that would be a tremendous waste of resources that could be better-spent elsewhere. Like transporting supplies for the troops on the ground. You only bust out the planes when you have solid, definitive, verified evidence that there is something that should get blown up.
Drones flip that around. You can't quite go cruisin' around just looking for stuff, but it's worth the time & effort to check out quite a few of your semi-sketchy tips. Now you're doing a lot more operations, on less-reliable intel, and the risk of cock-ups rises significantly. But because the drones are remote, none of that risk is borne by any member of the military performing the operations; all the extra risk falls on the local civilian population. I don't think many people partaking in these operations are intentionally heartless, but this is a classic case of moral hazard, and on the margin more aggressive, risk-taking behavior is incentivized.
Additionally, putting a drone in the sky is faster than putting a regular plane in the sky. This means that planes tend to be used only against 'static' targets, which gives you an opportunity to scout & verify. Drones allow you to hit 'time-sensitive' targets, which means you are now making time-sensitive decisions. A wedding party got hit because some dude had literally minutes (or less) to decide if a collection of vehicles was a wedding or an armed convoy. I take it as axiomatic that the added time-pressure increases the number of wrong decisions.