Central planning is useless if people will not follow the plan. Socialists must have the ability to ensure the plan is enforced. By nature they become intrusive, and often repressive.
In capitalism, everyone follows their own plan, so no central enforcement is needed.
Ergo, capitalism creates freedom, socialism does not. However, socialism empowers leaders, so governments always seek to become more socialist.
One of the most important findings of the Austrian school of economics is that central planning is useless even if people follow the plan. Without feedback in the form of relative prices, central planners cannot possibly plan and direct an economy.