Why are multistage rockets used to launch spacecraft from the surface of the Earth?

This is necessary for a more rational use of fuel resources: after the full depletion of fuel, the next spent stage is separated, so that the rocket fuel is no longer spent on accelerating this unnecessary stage, the mass of the rocket also becomes less. Therefore, a multistage rocket can reach a speed greater than each stage separately. In theory, single-stage missiles are also possible, but they would be too expensive. For the first time the idea of ​​using multistage missiles (for military purposes) was put forward during the First World War by the American Robert Goddard, but its most famous popularizer was the brilliant Russian self-taught inventor Konstantin Tsiolkovsky.