Everything you just said is true of rifles, grenades, swords, and spears.

Drones are weapons. They're one of the many tools of war. But war has always been about culture, food, politics, religion, demographics, and many other factors.

People win and lose wars. Weapons help.

Throughout history ordinary soldiers were often unwilling to fight against people from their own community. This often limited how authoritarian governments could respond to public unrest forcing them to accept reform or even leave power. Obviously they tried solving this by stationing troops far away from their home regions, creating various elite forces/deaths squads etc. But these all very expensive and/or required significant forethought.

Drones on the other hand are cheap and require fairly few people to operate. A few deaths squads in the control might be enough to suppress an entire country.

Mind you, the Assadists came out on top in Syria; they don’t use drones so much, but old fashioned siege warfare against population centres, terror bombing and chemical weapons.

Is not dying to something you cannot even see, that drops grenades on you or fires rockets at you a hit to morale?.

As I understand it, once you have already joined a guerilla organization like the Taliban, you have generally made peace with the fact that the drones are there. Watching someone die by hellfire missile strike further confirms that the evil people who are oppressing you by drone need to be stopped. Also, showing other people the aftermath of a strike helps to convince them to support you because they think they might get caught in the friendly fire.

It's a little like surrounding an army on an open field: If you give the losing side in a pitched battle an escape route, many of them will run, but if you surround them, they will fight to the death because there's nothing else they can do.