Under our system of government created by the Constitution, steps were put in place to prevent any branch of government from becoming too powerful. Creating a separation of powers and a system of checks and balances did this. With the separation of powers, each branch has a different job. The legislative branch makes the laws. The executive branch carries out the laws. The judicial branch interprets the laws.
Additionally, each branch can control the other branches. The president can veto laws of Congress. The Congress can override a veto of the president with a two-thirds vote of both houses of Congress. The courts can declare laws unconstitutional meaning the laws can’t go into effect. Congress can impeach judges and the president. As of a result of these and other checks and balances, no branch should have too much power or be more powerful than another branch.
Some people feel Congress has a great deal of influence because any bill that requires money to be spent has to start in Congress. However, with the system of checks and balances, this power can be controlled to some degree.