Guns don't do anything without bullets. Bullets don't do anything if they don't hit a target. Disable power and communications and most people become immediately useless at living, let alone mounting an assault.
The days of sheer numbers being useful are long past in the era of modern warfare.
Not really. The US followed certain rules of engagement in Iraq and Afghanistan that a truly ruthless military would not.
For example the Battle of Fallujah was fought with Vietnam level tactics. There were about 100 KIA for the US side. The battle could have been fought differently with zero US losses.
The days of sheer numbers being useful are long past in the era of modern warfare.