Not to enforce border patrol. They are used against enemy combatants. If you are against weapons that kill at a distance, you might as well complain about the invention of rock throwing. Regardless, that is an entirely different situation.

I don't see a problem here. There are remote controlled cameras surveilling the border. That's a long way off from remote controlled guns patrolling the border. And an even longer way off from autonomous guns patrolling the border.

The only reason guns have been legally used at the border is when an agent's life is in danger. Agents can't just shoot a migrant to stop them from crossing the border. So what good is a gun going to do on a drone dog? You're just making up non-existent problems.