The essence of the doctrine of separation of powers is to prevent

The doctrine of separation of powers divides governmental authority among three distinct branches: the legislature (which makes laws), the executive (which implements laws), and the judiciary (which interprets laws). Each branch operates independently within its sphere, and no single branch is permitted to exercise the powers belonging to another.

The central purpose of this arrangement is to prevent the abuse of powers. When all governmental power is concentrated in one person or body, there is a high risk of tyranny and arbitrary rule. By distributing powers across three branches and establishing a system of checks and balances, the doctrine ensures that each branch can restrain the others from exceeding their constitutional authority.

Independence of the judiciary is a result of separation of powers, not its core purpose. Financial independence is not directly addressed by the doctrine. "Friction of powers" is not a recognised political concept in this context. The overarching goal is safeguarding citizens from the concentration and misuse of governmental power.