Many people have the wrong idea about Daleks, seeing them as some kind of manufactured, malevolent robot army. They’re not. What people see and term a Dalek is merely an outer, protective shell, a technologically enhanced suit of armour, designed to contain and protect the otherwise vulnerable, even fragile biological entity that is a Dalek’s true form.
Without their battle armour, they’d be far less of a threat and far easier to kill, but with it, and the added advantage of their powerful fleet of spaceships, they’re almost unstoppable. Proof that technological superiority is ultimately more important than physical capabilities.