Ukraine

Drones can't take prisoners when they're way behind enemy lines. Normal face-to-face combat allows for surrender, but how can a drone take control of an enemy combatant who surrenders 5 miles behind the lines? That's why you see drones killing the wounded and unarmed. Until they are dead they are an enemy asset that is irretrievable. It's the same reason abandoned enemy equipment is destroyed. If it can't be captured, you don't want the enemy to fix it up and continue using it.

Most Russian soldiers know they can surrender, but they risk being shot by their own troops. Many have families back in Russia who would suffer if they surrender. Some have no idea where the Ukrainian lines are, and walking around way behind the lines is an invitation to the drones. Others have bought into the Russian propoganda about life as a prisoner of war in Ukraine. And some just have too much machismo to surrender. They'd rather die. Surrenders typically happen when there's close combat.