They run out of power in ONE HOUR or less. Until that problem is solved they are not a serious threat.
The mistake is thinking a combat robot has to look like a human.
We live and workaround hundreds of robots (machines doing things we humans once did). None of them look like humans. I can see a future war where drones do most of the patrolling and ambushes.
There could be a many different combat robots all looking different depending on their mission. As for power, rechargeable batteries and solar.
There will be problems, but that is what research and development is for.
There are three inventions that changed war forever.
The machine gun.
The Tank
The Airplane
When each was introduced in war the Generals did not know what to do about them. The first nation that did had the advantage until others caught up.
This is going to be true with “robots” in combat. It is going to be a game changer
And none of which runs on batteries.