Off-Beat Subject for the Poli Board - Why don't we already have Ground Combat Drones?

No, I'm not talking some terminator shite. But given that we already have armed flying drones manned by people sitting at a terminal here in the states, it just doesn't seem like a grand leap to have small wheeled vehicle drones equipped with some type of small arms that we could field by the hundreds that were just armored enough to repel small arms fire.

Think of the limitations removed.
1. The obvious. Not human loss if blown up.

2. Human soldiers have a limit to the amount of ammo they can carry. So would the drone but I suspect it would be about 10x as much.

3. Drones don't need a supply chain......or at least not as large a supply chain. You don't have to feed them. And, they can drive BACK to the supply depot for shite like fuel/maintenance. You don't have to fly the shite to them.

4. The frickers could be networked. They would each know where the other is and maintain their spacing / intersecting fires almost perfectly.

5. I submit they'd kill fewer civilians because humans are firing under duress. IE....you come around that corner, you're shooting that fricker if he moves. If it turns out to be an 8 year old, human error. BUT, if you are watching it on video, you ain't scared. You can hesitate until you know it's not an 8 year old. So what if he gets a shot off first. You're armored AND, you're chillin in the U.S.!

6. I'm not even convinced that they'd be more expensive than human infantryman. Humans require salaries, health insurance, life insurance, family health, retirement etc etc.

So, what say ye? Doesn't this seem like something we will be seeing in the relatively near future? (20 years or less?)